[Train whistle blows] ♪ Anything else, Miss Christie?

No.

Thank you so much.

♪ Woman: Oh.

Thank you very much.

Oh.

Here they are.

♪ Oh.

Good morning.

Good morning.

Good morning.

♪ That's funny.

I have one of hers with me, too.

Oh.

Here.

Oh, yes.

That's a good one, but I guessed the ending.

Hmm?

This is her new one.

She must be worth a small fortune by now.

If she's got anything left.

How do you mean?

Well, I hear she drinks like a fish.

[Laughs] [Whistle blows] [Train whistle blows] Lucy Worsley, voice-over: Agatha Christie recounted this story in an interview in 1970, and I love what it tells us about her.

She was stupendously famous, yet she was able to slip beneath the radar.

They thought that she was a drinker, but, in fact, she was teetotal, and I think that this story is key to understanding who Agatha Christie had become in later life.

At the height of her fame and success, she reveled in being mysterious.

The greatest mystery that Agatha Christie ever created was herself.

♪ ♪ In the spring of 1930, Agatha Christie traveled alone to visit ancient sites in the Middle East.

♪ [Men speaking Arabic] Worsley: Aged 40, she was an internationally successful novelist, but she was also emerging from a tumultuous few years.

♪ The death of her mother and a divorce from her unfaithful husband had led to a personal crisis played out in public.

The trip abroad was an escape, an opportunity to take stock and rebuild far from press intrusion.

She joined a dig being run by a British couple-- Leonard and Katharine Woolley.

♪ Agatha knew that traveling would help her to escape from her problems at home.

What she didn't know was the completely transformational effect that the Arab world would have on her life.

Partly this was the culture shock of being a single woman from Devon in an environment like this, but on top of that, there was the actual activity the Woolleys were here for.

♪ There was something about an archeological dig that lit Agatha's fire.

The Woolleys' dig was in Iraq.

This one, in Egypt, is led by mother-and-daughter team Elena Pischikova and Katherine Blakeney, who've been working here for over 15 years.

♪ Aha.

This is your site.

Pischikova: Yes.

Hi, Lucy.

I'm Elena.

Thank you.

Thank you.

Thank you for having me.

It's lovely to meet you.

May I take a tour?

Absolutely.

You want to see the tomb of Karakhamun?

I do you want to see the tomb.

Thank you.

Oh, aye.

♪ Worsley, voice-over: I've always wondered why Agatha, the crime writer, was so drawn to archeology, and I think I've come to the right place to find out.

Worsley: I understand that you are Agatha Christie fans.

Am I right?

Huge, huge fans.

Huge.

[Laughter] What draws you to Agatha?

She's a brilliant writer.

brilliant writer, and her approach to everything is very archeological.

She treats every object as an incredible find, actually.

You like Agatha Christie because she treats objects, clues, things as important in the way that an archeologist does.

Exactly.

Yeah.

She goes into this really poetic description of a dagger being discovered in the glint of gold, and it's very romantic.

Every person, every clue, absolutely everything is celebrated by Christie, and that's what they call archeological mind, and that's what I admire about Christie.

[Men speaking Arabic] ♪ Worsley, voice-over: Agatha's passion for archeology would offer her more than just literary inspiration... ♪ because on this trip, she met a 25-year-old archeologist called Max Mallowan.

He'd been tasked with accompanying the famous author around the sites.

♪ Despite being 14 years her junior, something clicked between them.

♪ Of course, this wasn't at all a romantic relationship.

There was the age gap, and they were so different... ♪ but then, boom, just months after meeting her, Max asked Agatha to be his wife.

She was thrown into turmoil.

Max was lovely.

She'd been able to relax with him, and he was offering her a life of travel and adventure and his passion for archeology, but her demons were never far away.

Her first husband Archie had betrayed her, leading to a painful divorce.

The memories were still raw.

Something of her feelings enters into her writing.

Here's "Murder in Mesopotamia."

This book draws heavily on her experience of archeology in the Arab world, but I think she also gives us a glimpse into her own heart.

She has one character who's lost a husband, say this.

"Lots of people wanted to marry me, "but I always refused.

"I'd had too bad a shock.

I didn't feel I could ever trust anyone again."

♪ It took Agatha months to make up her mind, but at last, her feelings for Max won out, and in September 1930, just 6 months after they'd met, they got married.

This is a letter that she wrote to him on Christmas Eve of that same year.

I love this letter.

Christmas Eve had been the date of Agatha's first wedding to Archie, so the anniversary of that, as she says here, "It's always been a sad day for me-- "but not this year.

"I feel so happy and safe and loved.

"Bless you, my darling, "for all that you've done for me and given back to me."

♪ This newfound happiness had a profound effect on Agatha's work and ushered in a golden age for her writing.

In the next 9 years, she would go on to write an incredible 17 full-length novels... [Camera shutter clicks] and in that time, every year, the happy couple returned to digs abroad.

♪ Agatha and Max's shared passion for archeology was never far from her thoughts.

In one book, she even has the great Poirot refer back to that case he cracked in Mesopotamia, and she has him draw a parallel between the work of the archeologist and the work of the detective.

They do the same thing, he says.

"You take away the loose earth... you scrape here and there with a knife," removing "the extraneous matter so that we can see the truth-- the naked shining truth," but this book wasn't set on an archeological dig.

It wasn't even set in Iraq.

It's the story of a death on the Nile.

♪ In 1931, Agatha and Max went to Egypt.

They became friends with Howard Carter and visited the tomb of Tutankhamun he'd discovered... ♪ and they came here to the Temple of Karnak... ♪ which Agatha described as one of the great beauties of Egypt.

♪ In the early 1930s, Egypt had become a popular destination for British travelers.

Tourists like Agatha flocked to the ancient ruins, which meant Egypt offered her the perfect setting for her new book, one she knew would resonate with her readers.

In "Death on the Nile," Agatha would develop one of her favorite plot devices-- the closed circle, you know, when she seals all the suspects into a particular place, has to be one of them.

She'd used this way back in her first book, "The Mysterious Affair at Styles," when it had been the country house.

In "Murder on the Orient Express," it had been the train, and now she'd pick a setting that, to most of her readers, would have seemed exotic and glamorous.

♪ This time, her closed circle would be a luxurious paddle steamer on the Nile.

♪ Agatha and Max boarded this very boat in 1933.

The S.S. Sudan was built in 1885 for Egypt's royal family and later converted into a cruise ship for wealthy tourists.

On the surface, "Death on the Nile" is classic Christie.

A rich cast of characters is trapped on the boat, and when a murder occurs, Hercule Poirot is on board to solve the case, but it's more than that.

In this book, Agatha uses her own observations of love, marriage, and betrayal as the engine of the story.

♪ I've been reading the book again, and I've noticed it's also got another one of Agatha's favorite devices in it--the hidden couple.

To explain how this works, I'm going to have to do a bit of plot spoiling.

The story starts with Jackie and Simon, who are in love, but they're very poor.

Jackie has a plan, though.

She asks her friend Linnet, a rich American, to give Simon a job.

Linnet says, "Absolutely."

Everything is going very well.

Fast-forward 3 months, and Simon, mm, the cad, he leaves Jackie and goes off with rich Linnet instead.

They get married.

They go on their honeymoon to Egypt, ah, but who should turn up like the ghost at the feast?

It's the jilted, troubled Jackie, who follows in their footsteps.

Everywhere they go, she seems to be there, too.

There's definitely going to be trouble.

♪ [Bird squawks] Linnet asks for Poirot's help, and he agrees to talk to Jackie to tell her to back off.

"Mademoiselle," Poirot says to Jackie, "I speak as a friend.

"Give up the past!

"Turn to the future!

"What's done is done.

"Bitterness will not undo it.

You're young, you have brains-- the world is before you."

Poirot might almost be talking to a younger Agatha here after she'd been betrayed by her first husband Archie and bitterness had entered her heart.

Poirot goes on to say to Jackie, "Do not open your heart to evil because if you do, evil will come"... ♪ but this being Christie, evil is never far away.

[Gunshot] Linnet is murdered in her sleep.

[Camera shutter clicks] Jackie is the obvious suspect, but she has a watertight alibi.

So does Simon, Linnet's husband, who stands to inherit her fortune.

Finally, though, Poirot is able to unmask the villain... ♪ or villains because secretly, Simon and Jackie have been in cahoots all along.

Simon had only pretended to fall in love with Linnet.

He married her so that when she was dead, he could inherit the money and share it with Jackie.

Agatha is so clever at the way she misdirects us, she makes us feel sympathy for poor, lonely Jackie, jilted at the altar.

She makes us feel sympathy for Simon-- who's lovely, young wife has been killed-- when all along, these two have been the villains.

♪ "Death on the Nile" has it all-- the glamorous, romantic setting, the stunning plot twist, but I think its success is down to the personal experience Agatha brings to it which resonates through the novel.

It's great to think of Agatha walking around that boat, checking it out, making sure the plot worked, but on top of that, it's a bit sad to think of her perhaps thinking about her own past.

That story definitely has the emotional charge that it carries because of her own experience of betrayal and of the destructive power of romantic love.

♪ Agatha and Max loved Egypt and Iraq, but they made their home in England.

♪ [Bell ringing] Its towns and villages shaped so many of her novels.

For Agatha, the county of Devon in particular exerted a gravitational pull.

Agatha still owned her old family home of Ashfield, but somehow, going back didn't feel right for her and Max.

It was too bound up in the trauma of her youth-- the death of her father, the family's financial uncertainty, and the oppressive grief of her mother-- but then Agatha became aware of a house for sale on the River Dart.

Here's the advert in "Country Life" magazine.

It was huge.

It has stabling for 7 horses, a billiard room, 10 bedrooms, 6 more bedrooms for staff, and it was advertised as being eminently suitable as a first-class hotel.

[Clang clang] ♪ May I come on?

Please do.

Thank you.

Shall I get down there?

Yeah, right here.

♪ Worsley, voice-over: It was a sign of the times.

In interwar years, the English country house that had dominated so many of Agatha's novels was in decline.

Now they were more likely to become hotels or boarding houses.

Only a bestselling author could afford to buy a house like this to live in it.

♪ Agatha fell in love with the house and bought it on the spot.

♪ Agatha and Max were putting down their own roots in Devon, and Agatha's writing that year was directly inspired by the landscape that surrounded them.

♪ In 1938, the year Agatha bought Greenway, she wrote a new story set on an island, and the island was crowned with a beautiful, white house, she wrote.

Now, this story's clearly set in Devon-- Plymouth's mentioned; so's Exeter-- but could the island itself be a real place, too?

Well, here's a clue.

That same year, she wrote another story set on an island.

This is her notebook where she was planning it all out, and she's written here, "Scene: Hotel on island-- Bigbury."

Now, Bigbury is definitely a real place.

It's only 20 miles away from here.

There it is, and--guess what-- right by Bigbury, yes, there is an island.

♪ Agatha had stayed at Burgh Island Hotel in the 1930s.

At high tide, the sea cuts it off from the mainland.

♪ [Engine starts] The only way across is by sea tractor.

♪ That's it.

We're in the water now.

♪ Its unique location would spark Agatha's imagination.

♪ [Gull squawking] We've crossed the sea, and we've arrived at this mysterious, isolated island.

♪ Just as in Agatha's day, Burgh Island is fun and glamorous... ♪ [Gull squawking] but one of her most famous books made this setting a much more disturbing and menacing place.

♪ A group of strangers-- they don't know each other-- have been brought to an island.

They've been invited to stay in a mysterious private house with a mysterious owner who isn't even there, and in Agatha's version of Burgh Island, there's no sea tractor.

There's no causeway.

There's no way of getting off the island.

There's just the treacherous sea.

It's the classic Christie closed circle, but this time, there's no Poirot.

There's nobody on the island at all who represents the force of good.

Be very afraid.

♪ As the story unfolds, each of the 10 guests dies, and then there were none, as the title goes... [Gull squawks] except that wasn't the original title.

When the book was first published in Britain, the title notoriously contained a racial slur--the N-word.

Obviously, this is utterly offensive.

Why would anyone want to read this book today?

The offensive title came from a nursery rhyme.

It was also found in blackface minstrel acts, racist theatrical performances.

Frankie Bailey has studied race and crime fiction.

What would you say if I asked you if you liked and admired Agatha Christie?

I admire her as a writer.

She's a master of that 3-act construction.

She's, you know, very efficient in terms of how she goes through the book, building the suspense, alerting the reader that something bad's gonna happen, but you don't know quite when, and in this case, she's telling us that they're gonna die one at a time, as in a serial killer movie.

She's the queen of suspense in that respect.

I think she does that as well as-- or even better, in some cases-- as Alfred Hitchcock, who's my favorite director of all times.

The offensive title wasn't on the front cover of the first American edition, was it?

No, which is interesting because we got the same nursery rhymes, but I think by 1939, we got Roosevelt is in the White House.

Things are beginning to improve, and you don't want to put that out there.

If you offend people and have people boycotting your book, then it's not gonna do well.

Yeah, so the publishers in America thought, "This racial slur will not sell here."

It was unnecessary to what they wanted to do.

Worsley, voice-over: In the USA, another title was used for the book and a film adaptation.

It was also a racial slur, against Native Americans.

Meanwhile, almost unbelievably, in Britain, the N-word title was still in use until 1986.

Now, some people would say that this kind of offensive title is typical of her class and time, but that's not a "get out of jail free" card, is it?

No.

It's not.

It is disappointing, but Agatha Christie is a woman coming out of that colonial background.

She's, you know, well-read, well-educated, and she's coming out of a fairly elite class, and she's not writing to change the narrative.

She's writing so that she's writing for that white audience, that white European, white American audience, and she is picking up where they are and not advancing that discussion.

Which is why, as a historian, I think we have to look at this stuff and appreciate that it was there and to understand how potent it was.

Exactly.

We need to understand it in context, knowing that Agatha Christie was not alone in terms of what she was doing.

Writers in the United States and elsewhere, here in England, you know, everyone was writing in this vein and using this kind of language.

That's interesting.

You find it possible to say, "She's a good writer.

"There are some things that aren't acceptable that she wrote."

Because if I ruled her out, I would be ruling out a lot of other writers during that period.

There are things you can learn from reading those writers.

Frankie, you're saying this is complicated.

It is complicated.

We can't just put people into these boxes of good and bad.

Right.

♪ Worsley, voice-over: "And Then There Were None" is said to be the bestselling mystery novel of all time, and it was published just weeks after Agatha and Max heard an announcement on the radio in the kitchen at Greenway.

Neville Chamberlain: I have to tell you now, this country is at war with Germany.

[Siren] Worsley, voice-over: Having survived one world war, the prospect of another one must have appalled Agatha and it threatened to upend her newfound security.

In September 1940, the Blitz on British cities began.

Children were being evacuated from places like London to the safety of the countryside, but Agatha was going in the opposite direction.

She even rented out her Devon house Greenway to be a home for evacuees, and the reason she came here to Blitz London was to be with her beloved Max.

♪ With his archeological career on hold, Max had taken a desk job with the RAF... ♪ and in March 1941-- 7 months into the Blitz, which killed almost 20,000 people in London-- Agatha moved with Max to this ultra modernist block of flats in Hampstead.

♪ These were dangerous times, and this was a dangerous street.

Before Agatha moved in, a bomb blew out the glass of all the windows of this building, and over the 8 months following, 38 bombs fell on this neighborhood, but Agatha herself wasn't particularly fazed by this.

She tells us that she never bothered to go down to the shelter, and if she was woken in the night by the sound of bombs falling, she'd just say to herself, "Oh, dear.

There they are again," and she'd turn over, and she'd go back to sleep.

♪ Was this genuine calm in the face of mortal peril or a reflection of Agatha's state of mind?

The bombs might not have bothered Agatha, but something else was up.

In February 1942, Max volunteered for a job in Cairo.

He was going back to Egypt, where they'd been so happy together, but this time, he was going alone.

These are letters Agatha wrote to Max, and I think they show evidence of deteriorating mental health.

She has dreams that he's abandoned her.

Listen to this.

"They told me you no longer cared or wanted me "and had gone away.

I woke up in a panic," and then again, "I feel so afraid sometimes.

"Write often because I need cheering when there are no sunny days."

Now, Agatha had come to London to be with Max, but he'd gone off to North Africa.

He was living there in a sunny climate with lots of other British people serving in the forces, all of them away from their families, some of them women his own age.

If Agatha still had any insecurities about being older or about what had happened in her first marriage, they must have come flooding back.

♪ Lonely and jealous, the clouds of her past turmoil were gathering again, so to keep them at bay, Agatha poured herself into her work.

In the war years, she wrote 16 novels, 7 collections of short stories, and a play.

Agatha tells us that she wrote one of these wartime books in just 3 days.

She describes producing it in a white heat.

She didn't dare leave it and go and do anything else.

She says, "I had to go on with the book until I'd finished it."

When she finally got to the end, she collapsed.

She slept for 24 hours, and she later said that this book was the one book that had satisfied her completely.

She called it the book she'd always wanted to write.

♪ It wasn't a detective novel at all, and it didn't even have Agatha's name on the cover.

Written under her pseudonym Mary Westmacott, "Absent in the Spring" is in part about a woman who comes to realize that her marriage is a lie, that her husband loves another woman.

"Rodney and I have been perfectly contented with one another."

"Of course you always were as cold as a fish, Joan.

"But I should have said that husband of yours had quite a roving eye!"

"Really, Blanche!"

"Joan flushed angrily.

"A roving eye, indeed.

Rodney!

"And suddenly, discordantly, "a thought slipped and flashed sideways across the panorama of Joan's mind."

In 1943, no one knew that Mary Westmacott was really Agatha Christie, and I think Agatha was reveling in the freedom this gave her, the freedom to be off brand.

These Westmacott books really are her most personal, her most intense works.

I believe that when she'd started to write them years earlier, it had almost been under doctor's orders as a kind of therapy because she'd been struggling with her mental health, and by the time we get to the war, I think that was happening once again.

Max was away.

She was lacking support.

She was in a bad place emotionally, but when she was being Mary Westmacott, she was writing herself better.

♪ Agatha was used to writing her own life and emotions into her books, but sometimes she found inspiration in the unlikeliest and darkest of places.

♪ In the summer of 1944, 3 brothers from South Wales were taken to Shropshire.

Their parents had been deemed unfit to look after them, so they'd be fostered.

♪ Dennis O'Neill was 12.

Terence was 9, and Freddie was 7.

[Camera shutter clicks] The two older boys were taken in by a couple called the Goughs, who lived in a remote farmhouse.

♪ The farm was in rolling countryside.

There were chickens and cows and a vegetable garden.

When Terence arrived, Mrs. Gough gave him a kiss and said, "Welcome to Bank Farm.

You'll be very happy here."

Little while afterwards, the boys had to write an essay at school about their parents.

This is what Terence wrote.

"My mother is very good and kind to me, "she buys me new clothes... she gives me lots to eat, and lots of cake."

Later, Terence revealed that this was all a fantasy.

As he says here, "I knew instinctively that I would be "in huge trouble if I told the truth "about the way the Goughs were treating us.

"The lack of food, "the scratchy straw mattress, "the heavy workload, and the stripes."

That's the wounds they got from the beatings every night.

♪ Dennis O'Neill died of injuries inflicted by his foster parent Reginald Gough.

The horrific case made headline news, and one person who read all about it was Agatha Christie.

♪ Years later, she wrote, "There was a case once "where children had been neglected and abused "after they had been placed by the council on a farm.

"One child did die, and there had been a feeling "that a slightly delinquent boy might grow up full of the desire for revenge."

The O'Neill case gave Agatha the germ of an idea that she used for a 30-minute radio play called "Three Blind Mice."

Here's the notebook where she's working on the idea, and she's done the title as a pictogram-- 3, blind-- that's an eye crossed out-- and then a cute, little mouse-- but she couldn't use that title when she expanded the radio play into a full-length stage play.

There was already a play with that title.

She was stumped.

She just couldn't think of an idea for what to call it until somebody came up with a stroke of genius.

It was to be called "The Mousetrap."

[Applause] ♪ On the surface, the play Agatha developed is a classic Christie whodunit.

[Windlike whirring] A group of unconnected strangers arrive at a guest house.

♪ They become trapped there by bad weather.

♪ It's another closed circle, but soon, Agatha will weave the O'Neill tragedy into the drama.

The play begins in quite a lighthearted way, but Agatha is so good at light and shade, things soon turn dark.

There's been a murder.

A policeman arrives at the house to follow up a lead, and he tells everybody that the victim was a woman who years before had been responsible for the death of a little boy in her care.

Was she murdered in revenge?

♪ Taking inspiration from the real-life O'Neill case, Agatha imagines that the surviving brother could be the vengeful killer.

The first suspect in "The Mousetrap" is a young man of the right age.

Could it be him?

"The Mousetrap" opened in 1952, and it's become the longest running play in theatrical history, but could its success in part be down to a real-life tragedy?

Do you think that the people sitting here watching "The Mousetrap" in 1952 would have remembered the O'Neill case?

It was in 1945 a very important case, this awful story of the boys who were sent into foster care.

This forms the backstory of "The Mousetrap."

It's not the actual action of the piece, but it is referenced throughout it as one of the reasons for the motivation of the characters and the reason why people are there.

For the audiences of 1952, yes, it would have been fresh in their memories.

They would have understood the referencing in the play.

Now, we believe that Agatha Christie was inspired by the O'Neill case for writing "The Mousetrap," but is there any actual hard evidence of that?

Well, have a look at this from the Agatha Christie archive.

It's a newspaper cutting from 1966 from the "Sunday Mirror" which obviously caught Agatha's eye.

And she's written on it-- this is brilliant-- and what does it say here?

"From this real life--" "From this real life happening..." "Happening."

That's what it says.

"I took the idea for the Mousetrap."

"Mousetrap," and I like the way she's signed it, "Agatha Christie."

She's written that for posterity.

She's written that for us.

It's endlessly fascinating to me.

People think that Agatha Christie somehow celebrates Britishness, that she's, oh, sort of the tourist marketing board image of Britishness.

I imagine you'd disagree.

There's nothing cozy about "The Mousetrap."

Over time, I think people began to appreciate exactly the significance of what it was talking about.

Harold Hobson, the great "Sunday Times" theater critic, wrote an article about "The Mousetrap" in which he attributed its success to the fact that it was what he called a parable of our times.

Everybody in it is displaced.

Everybody in it is suffering from post-war anxieties.

This is, you know, not a country house, but a country house that's been turned into a guest house in order to make ends meet.

This is people having strangers in their house after the war.

The suspicion of the stranger very much comes through in the play, and you have, perhaps, one of the most radical images on the London stage at the time, which is, the lady of the house carries a vacuum cleaner across the stage.

Now, we have to contextualize this in that, you know, 4 years later at the Royal Court, John Osborne's "Look Back in Anger" is thought to have, you know, recalibrated the entirety of British theater by showing a woman doing the ironing, you know, which was-- This was not the kind of thing you went to the theater to see.

But Agatha Christie was doing it first.

Exactly.

As well as this extraordinary background story, it works very well as entertainment, and people like to be entertained.

It's got a lot of comedy in it.

It's got a lot of very good characters, and it's got a really fascinating plot with one of the most legendary twist endings in theater of all time.

♪ Worsley, voice-over: In the 1950s, with the troubles of wartime behind them, it was back to Greenway.

♪ The house became a happy family retreat full of food, laughter, and fun.

Agatha's contentment was complete.

[Conversation and laughter] This is one of my favorite letters that Agatha ever wrote to Max.

"Darling!"

she says, "You are 40 to-day.

"Hurrah!

At last!

"It makes a big difference to me.

"I feel it closes the gap a little.

"When you were in the thirties and I had reached the fifties, it was pretty grim."

As Max was settling into comfortable middle age, perhaps some of Agatha's old insecurities were melting away, and she was also closing the age gap with somebody else who was very important to her.

♪ Agatha's creation Miss Marple, the shrewd and observant old lady detective, appears in 12 novels, most of them from the postwar years.

Now, I think the very best Poirot novels are from the twenties and the thirties, when Agatha was young.

In 1950, she turned 60, and from then on, she and Miss Marple would get older at the same pace.

They go through life together, almost as if Christie and Marple were the very same person.

♪ Agatha inhabited Miss Marple inside and out.

She was so immersed in Marple's stories that she grabbed anyone she could to help perfect their brilliant plots, including getting her neighbors to act them out.

♪ Agatha had the neighbors come into the drawing room, and she stationed one of them behind the door.

This would be significant.

Then she turned off the lights and came in waving a torch around.

♪ Then the lights came back on again, and Agatha asked everybody to explain what they'd seen.

Of course, all the neighbors said, "We saw nothing.

We were dazzled by the torch," except for this person because this person was behind the beam and they could see what had gone on.

When the book "A Murder Is Announced" came out, the neighbors all realized that they'd been part of a kind of a novelist's field experiment to test out this really crucial aspect of the plot... [Birds chirping] ♪ [Birds chirping] but the Marple stories are more than just cunningly plotted and deeply satisfying crime novels.

I think that they document a changing British society.

Caroline Crampton is a detective fiction podcaster... Come in for a cup of tea.

Worsley, voice-over: and fellow Christie fan.

♪ Worsley: We're sitting in a lovely village, just the sort of place that Miss Marple lived, but something's changing about these villages in the later Marple novels, isn't it?

In "A Murder is Announced," it's 1950.

We start to see the way the social fabric of England has changed.

People's lives were completely disjointed and fragmented by what happened in the war.

Once upon a time, everyone who lived there would have been known to everybody else, and if in the unlikely event that any newcomers arrived, they would come via some established network.

They would come with a letter of introduction from a friend or family member, and yet by the time we reach the post-Second World War period, people turn up all the time with no letter and no roots, and that's just how the world is now, and that change, that gap, Agatha Christie really inhabits and makes it work for her mystery.

In the story, Miss Marple even says, "15 years ago, "we would have known who everybody was.

Now we no longer do."

And that's the effect Christie's trying to create, I think, destabilizing these ideas of identity.

The way that she writes mysteries keeps pace with the way that the world is changing, so she's not trying to recreate the villages of the 1920s and thirties.

She's looking at the world as it is and going, "How can I use parts of this in order to write a really good plot?"

You know, Caroline, I think a lot of people would say that Agatha Christie was socially conservative, but her stories don't necessarily prove that, do they?

No.

There's one really good example of that in "A Murder Is Announced" where we've got an openly lesbian couple.

Miss Hinchcliffe and Miss Murgatroyd are just totally normal neighbors, and we even get a really emotional moment in that book when Miss Murgatroyd is killed and Miss Marple comforts Miss Hinchcliffe at the loss of her partner and that this is really tragic and devastating.

To me, it's quite amazing that a same-sex couple is just slipped into the landscape like that in commercial fiction in 1950.

That's really progressive.

It is and even subversive in a way, homosexuality not being legalized until much later, and yet it's completely normal in the book.

As we go on into the 1960s and Agatha Christie is now in her own 70s, how do the villagers change?

Well, everything changes about them.

St. Mary Mead is no longer this tight, closed little circle of a high street with a few different shops and a few cottages.

All sorts of modern ideas have arrived, including a supermarket instead of your individual grocer shops and things like people don't eat bacon and eggs for breakfast anymore.

They eat cereal for convenience.

It comes straight out of a box.

And yet a lot of people would say, "Well, all Agatha Christie stories "are set in the same year of roughly 1935," wouldn't they?

People get this idea of the fact that Agatha Christie can be identified with a specific era when actually, you know, she had a writing career spanning decades and she evolved through it.

♪ Worsley, voice-over: Part of that evolution involved a late reconciliation with the film industry.

The movie studios had come calling for Agatha's bestsellers from the beginning, but the truth was, she didn't really like the films of her books.

She struggled with seeing her detectives Marple and Poirot on screen, but in 1974, now an old lady, Agatha relented, and movie moguls persuaded her to lend them one of her biggest titles.

♪ "Murder on the Orient Express" was a huge hit, and Agatha was delighted.

♪ I think that in old age, Agatha wanted to give her most successful creation a life beyond her own to ensure that Hercule Poirot would live on for a new generation.

At the London premiere, Agatha, the Queen of Crime, was introduced to the Queen of England... ♪ but by now, Agatha's health was in decline.

She attended the premiere in a wheelchair.

♪ Agatha had ensured Poirot's legacy on the silver screen, but she also wanted to say a more personal good-bye to her cherished character.

During the Second World War and in fear for her life, Agatha had written the final Poirot novel, but she'd locked it away for a future date.

In 1975, sensing the end, Agatha published "Curtain: Poirot's Last Case."

In this story, Poirot, like Agatha herself, is now in a wheelchair, and right at the end, just before he dies, he says good-bye to his really old friend Hastings.

He says, "Goodbye, cher ami.

They were good days."

It's like Agatha's saying good-bye to her readers.

[Elgar's "Nimrod" playing] ♪ Agatha Christie died peacefully on the 12th of January 1976... with Max at her side.

♪ Ever the writer, she scripted her own funeral.

♪ She wanted a piece of music by Elgar called "Nimrod"... ♪ the name of the place in Iraq she and Max had excavated in their glory days.

♪ After Agatha died, this letter was found folded up very small in her purse.

Turns out, she'd been carrying it around with her for 39 years, and I can see why.

This is what Max had written.

"Sometimes, but not so very often "two people find real love together as we do.

"We know that what we have cannot perish.

"For me, you will remain beautiful and precious with the passing of years."

♪ Oh... ♪ The happiness at the end of her life and the success she enjoyed as a writer belied the tumultuous times she endured getting there, but that turmoil was the making of her.

Agatha Christie's dark, brilliant imagination was shaped by the upheaval of her own extraordinary lifetime.

Without all that, I don't think she would have become the pioneering author she was, and we would not have such a rich legacy of stories, a legacy that continues to captivate to this day.

♪ [Birds chirping] ♪ ♪ "Agatha Christie: Lucy Worsley on the Mystery Queen" is available on Amazon Prime video ♪ ♪