Whitechapel

I'd you'd found an arm. We found a torso.

The Thames Torso Mysteries - the women were never identified.

How did she die? She was poisoned.

If you want to find the other body parts, check the riverbank

from Richmond to Whitechapel.

It's her left foot. This belongs to another girl.

I'm afraid this is all we've managed to recover from the river

in the last seven days.

River Police reckon anything we haven't found by now we won't find.

It'll be out at sea. We'll work with what we have.

The cuts to the second victim were made with the same weapon

and I've identified the same toxin in the limbs.

I wasn't able to identify the poison using standard tests.

This is unlike anything I've ever come across,

so I decided to take the different approach,

and look at incredibly rare poisons I was unfamiliar with.

You found it? Cantharidin.

Cantharidin, or Spanish Fly,

has been regarded as an aphrodisiac for centuries.

It is, in fact, a highly toxic poison.

Ed, tell us what you found.

1772.

Two prostitutes were given aniseed balls laced with Spanish Fly.

They spent a week in agony and nearly died.

The man who poisoned them

was sentenced to have his head cut off, his body burned

and his ashes scattered. That man...

was the Marquis de Sade.

Now this is important. He wanted to excite their desires,

he wanted them to participate in an orgy.

And he didn't act alone.

His manservant procured the girls and took part in the orgies.

A couple, administering a lethal aphrodisiac

to satisfy their desires.

OK.

Miles.

I want you to have a really strong coffee.

I prefer tea. I prefer you awake.

Look, the baby's getting much better.

She slept for four hours last night. That clearly isn't enough.

I want you sharp. There's nothing wrong with my game.

OK, why am I not surprised?

I didn't realise it was a poison. I...

I've given it to Eva.

Oh, my God.

It makes you feel all warm inside, you know?

I was trying to spice things up a bit. It didn't kill her.

Well, you've got to tell the boss. No, you tell him.

If I do he'll look at me like I'm a pervert.

Oh, and if I tell him?

Um, sir?

Erm, it's come to my attention that there is a place in Whitechapel

where... where you can... where you can buy Spanish Fly.

What's wrong with coffee? I like this better than coffee.

Right, what are we waiting for?

Found it. This is what we're looking for.

Now everyone thinks we're a couple.

Well, they're used to weirder than that in here.

No ingredients listed.

Let's get it analysed, see if it's the source of our cantharidin.

Is this real Spanish Fly?

It's 100% genuine. Satisfaction guaranteed.

Has anyone been in recently, ordering large amounts?

Everyone buys it. Young. Old.

Enjoy. Oh, no, it's not... it's not for me.

Or him. It's, um...

Oh, never mind.

Ah, there you are!

Well it, er, might season your paella.

Is that a euphemism?

No, I mean it literally. It's cayenne pepper.

What, is that it? Yes.

It might create a sensation of warmth, but it's not an aphrodisiac.

I've had a look at all the commercial preparations

claiming to be Spanish Fly, and truth is,

not none of them contain cantharidin.

Oh, hello. Didn't hear you come in.

How's it going?

I've made a good start on US crime and I'm now tackling Europe.

You won't have room.

Ah, about that.

I was hoping we could knock through.

I noticed there's a usable space on the other side of this wall.

That's the ladies. Look, I need to know

how the Marquis de Sade obtained his cantharidin.

Well, I suppose he would have bought it from an apothecary.

It was even sold in some spice markets in Morocco,

to be added to tagines. But, er,

well, anyone can make it.

If you have some blister beetles.

Just one second.

Latour have been importing medicinal herbs and spices for 200 years.

They specialise in Chinese remedies and obscure medicines.

Like cantharidin.

They supply it to pharmaceutical firms

who use it to manufacture wart treatments.

So far so legal. Well, there's more.

Latour is run by Travis Underwood

and one employee, a woman named Heather Green.

Travis Underwood, married to Mary for 25 years. Two adult children.

Mary has a long-term illness and is registered disabled.

Heather Green is the intriguing one.

She's worked with Underwood for three years.

She has a Masters in anthropology. Now at the end of her masters,

she published this paper in an esteemed journal.

This is her study into the use of aphrodisiacs

in tribal medicine by indigenous tribes in the Amazon.

She was particularly taken by a love potion called Catuaba,

and she tried it herself.

Excellent work. This could be our couple.

May I ask what this is about?

We'd like to speak to yourself and Mr Underwood

regarding the sale of blister beetles.

Is there a problem? There might be.

Just the two of you that run this place?

That's right.

Must be intense, two people working together all day long.

What are you implying?

Do you have more than a working relationship with your boss?

You two spend all your time together, don't you?

Long shifts.

I bet you spend more time with each other

than you do with your families.

Are you romantically involved?

He's not my type. Nor is Travis mine.

Gentlemen. Travis Underwood.

DI Chandler. DS Miles.

I understand you're interested in our beetles.

Cantharidin, yes.

Well, the trade is tightly controlled and regulated.

Lytta Vesicatoria.

Urgh! Strong odour. Unmistakable.

Smells like mice. Quite.

You mustn't touch them.

They are highly irritant, even like this. They'll cause blistering.

They're a powerful aphrodisiac, aren't they?

Sought after for hundreds of years.

It's not an aphrodisiac. That's a fallacy.

It's an extremely unpleasant poison.

Somebody would be very ignorant to try to use it in that way.

Excuse me. A few months ago, we had an enquiry from a couple

who thought cantharidin was a love potion.

They came here? No.

We take our security protocol very seriously.

The only way to become a client is to contact us by letter

and have the correct permits and documentation.

The first letter we received was from the woman and we politely declined.

There was a second letter?

From the man. And that one was scary.

Two letters. One address.

The first letter, from Celeste Caine, is reasonable.

The second letter, from Max, is very angry.

He was furious we denied his wife and demanded, in very strong terms,

to know how he could acquire the live beetles.

A couple desperate to obtain cantharidin

and willing to make violent threats to do so.

We need to take a closer look at Celeste and Max.

The two letters asking about cantharidin sent to Latour.

The names are false. Well, no big surprise there.

Same fake address on both.

Turns out to be a big house converted into flats,

where all the post is dumped in the hallway - easy access.

A dead letter drop. So nothing to go on, I'm afraid.

Wait a minute. At first glance this letter from Celeste,

it's beautifully written, suggests an educated woman of a certain age.

This letter from Max is misspelled and chaotic

and suggests someone who didn't finish school,

probably institutionalised, and of low intelligence.

She's the brains, he's the brawn. Yeah, but here's the thing.

I think they're the same person.

No. No, he's right.

Look closely. Ignore the differences and focus on the similarities.

The height ratio and spacing are the same.

You took the course too? I did. 2010.

Huh, 2008.

Well, if the same person wrote these letters,

are we looking for a burly woman or a girly bloke?

This is our third girl.

Found this morning in the Thames at the Dartford Crossing.

But she has something to tell us.

A nightclub? Mm.

The stamp is still vivid.

I think this gives us a good idea of her last movements.

Can you find out which club uses this stamp?

Yes, sir.

Come on. Club crawl.

Club crawl? Yeah, get your dancing shoes on.

I like the sound of that.

She'd have felt like she was burning to death from the inside.

I'm afraid they never found the heads.

I want you to remember she was a real person, care about her.

Unlike anything I've come across.

I thought we should eat.

How come you don't go home after your shift?

Because of them. The dead girls.

I can't go home and switch the TV on,

not when there's three victims out there,

with no name, no identity.

It doesn't feel right.

Are you always this invested in your cases?