Original subtitles

1939.

War with Germany is looming,

and the British know they will need every advantage to stop the Nazis.

They create one in a small group

of brilliant mathematicians and scholars

assigned to work secretly

in a quiet country home called Bletchley Park.

With the help of a discovery first made

by Polish intelligence officers,

this team will work to break the key to the Enigma code,

the encryption used for German military communications.

This crucial step is the first of many

in the intelligence war waged by the Allies.

All wars change the world.

But none of them change the world like the Second World War did.

Japan's on the march.

Germany's on the march.

No one can imagine the nightmare they're about to unleash.

The most destructive war in human history.

Suddenly, the world is turned upside down.

And all hell is let loose.

The west is stunned by the speed of the advance.

You get the Allies led by the big three:

Roosevelt, Churchill, Stalin.

Men who are dealing with immensely complicated questions.

It's the biggest military operation of human history.

The Allies have to come together -

not just militarily but industrial scale.

It's a global perspective.

They have to fight in every climate -

from the Arctic, to the jungles of the Pacific

to the deserts of Africa and the depths of the ocean.

But there was no certainty of victory.

It was going to be a horrific bloodbath.

We see humans at their absolute worst,

how they treat other human beings.

And we see them at their absolute best,

willing to give their lives that others might live.

World War Two was a struggle

in which there could be one victor...

...and one vanquished.

In the summer of 1940,

Great Britain is threatened by Nazi Germany.

Adolf Hitler's armies have torn through Poland,

Scandinavia, and Western Europe.

Even France has fallen.

Prime Minister Winston Churchill fears Britain will be next.

The first few weeks of Winston Churchill's

prime ministership are probably the worst

and most disastrous weeks in the history of Britain.

The most catastrophic defeat on the continent of Europe.

Outclassed by the German Wehrmacht

and the Luftwaffe in the skies above.

Britain is facing defeat and starvation.

By 1940, the British position looks practically hopeless.

They've met the Wehrmacht a couple of times,

and on both occasions - Norway and Dunkirk -

they wound up running away,

evacuating from the continent under fire.

I think, when you face

the enormity of the challenge Britain faced in 1940...

if you're up against a stronger army,

you've got to find other ways to get round them.

The British have been working to crack enemy military codes

since the outbreak of World War One in 1914.

Alastair Denniston leads the British Government's

Code and Cipher School,

located at Bletchley Park,

an old manor house in the English countryside.

He served as an intelligence officer

in the Royal Navy in World War One,

and has spent his entire career in cryptology.

Denniston predicted that accurate cryptanalysis

of the Wehrmacht's codes would be

an important weapon in any war with Germany.

We talk about the German way of war.

Sometimes, we say "Blitzkrieg" or "lightning war."

It's about tanks. It's about aircraft.

It's about mobile infantry, and, of course, artillery...

...all working together in the greatest possible harmony.

They need to be able

to communicate with each other in real time.

Vast technical improvements in radio

in the '20s and '30s make this possible.

The radio is as important to the Blitzkrieg

as the tank or the Stuka dive bomber.

It is Alastair Denniston who realises

that this German reliance on technical means of communication

is also a real Achilles heel.

If someone can step into that communications loop,

they can intercept German reconnaissance reports,

German orders.

They can intercept, in a sense, German intentions.

Denniston understands that signals intelligence...

is essential to combat Germany's

new mechanised tactics.

If you don't have vast numbers of tanks

and you don't have the luxury of overwhelming military force,

you need to find a way to win a war.

And that can involve using a bit of this: intelligence.

It provides an incredible force multiplier,

particularly when you're outnumbered.

It may give you that chance that you never thought you had before.

But cracking the German ciphers is seemingly impossible.

They're created by a complex device.

The Enigma machine.

The Enigma machine itself looks like

a cross between a cash register and a typewriter.

And it's an electromagnetic machine

that scrambles plain text into a code.

You would press the key...

...and that instigates an electric pulse

that would run through a set of rotors.

As they turn, it produces what we call ciphertext.

If you press the D...

...it would come out as a T.

If you press the D again...

...it would not come out as a T again.

It would come out as a Z...

...or some other random letter.

The word "Hitler," for example,

if used in a message, is scrambled.

This version is sent using Morse code

to the operator of another Enigma Machine with the same settings.

When the encoded word is typed in,

it's possible to decipher the original message.

It was a unique machine. Germany was leading the world in this.

It turns every German frontline position

in World War Two into a veritable data

and information processing centre.

And to make the entire process secure,

there is the Enigma machine.

The Germans believe their signals are secure

because of the complexity hardwired into the Enigma machine.

The great thing about the Enigma machine is

the vast number of ways that it can be set up every day.

If I've got three rotors,

Each rotor can have one of 26 positions.

So that's 26 times 26 times 26,

which is 17,500 different ways of setting that up.

That sounds like a big number, but it's not.

Here is where it gets fun because, on the front of the machine,

the Germans have installed an extra device,

which is called "The Plug Board."

If you had ten cables,

it's 150 million-million different ways

to set up the plug board.

So if you multiply all these different options together...

...you end up with 156 million-million-million

different ways of setting it up, which is more, I think,

than there have been seconds in the universe.

The Germans figured -

and I think justifiably - that it was unbreakable.

But Denniston believes

it's possible to crack the Enigma codes.

He spends years recruiting mathematicians,

linguists, and scholars from Britain's top universities.

He reached out to the academic communities -

to Cambridge and Oxford - and he'd go to dinner with them.

And he was kind of sussing out, you know, who's good at this,

who might be useful, looking especially at mathematicians.

It was a professional challenge.

You're a mathematician. You've got a problem.

You want to solve that problem.

And here's the added benefit that you're doing it for your country,

and for your family, so that they don't have

to grow up speaking German.

A key recruit to Bletchley Park is

a young academic from the University of Cambridge.

An eccentric genius named Alan Turing.

Let me tell you a bit about my uncle, Alan Turing.

He has always been interested

in everything to do with science and maths.

He likes the planets. He likes chemistry.

He likes genetics.

But what he's really interested in is logic problems.

Mathematical logic.

Turing is only 27 years old,

but he's already a world-renowned leader

in the solving of mathematical problems

with the help of mechanical devices.

One of the greatest contributions that Alan Turing brings

to code-breaking in this era is

to understand that, to attack the Enigma machine,

the British will need their own machine.

Turing begins by studying

the critical work of Polish codebreakers.

Before the War,

these men built a machine that could sift through

the many variations of the early Enigma settings.

In 1939...

fearing the Nazis were about to invade their country,

the Poles presented their device to the British

and French Intelligence Services.

Turing now assembles a radically upgraded

British version of this machine: The Bombe.

It's huge. Imagine a wardrobe, maybe a bit bigger.

Very noisy, very clunky.

The British feed intercepted German signals into the Bombe.

Then, it rotates through the millions

of possible Enigma settings...

...and, by a process of elimination,

reduces these to a smaller number that can be deciphered,

revealing the original message.

This is a sort of behemoth,

the like of which has never been seen before.

It's got 100 rotating drums.

It's got 1 million soldered connections.

How is this monster going to deliver?

Turing and his team are in a race

against time and Adolf Hitler.

In August 1940,

his Luftwaffe begins to attack

Royal Air Force bases in the South of England.

The Battle of Britain has begun.

Hitler has ordered the Luftwaffe

to destroy the Royal Air Force and its bases

before he invades Great Britain by sea.

The defence of the country depends

on the young RAF pilots and airmen sent up to defend Britain.

At Bletchley Park,

Turing and his team have been working to improve the Bombe.

And now, they're decrypting the Luftwaffe's Enigma signals.

You have got these extraordinary individuals -

certainly not your carbon-copy military types -

who have achieved what was believed

to be impossible.

Turing calls his new machine "Victory."

After decryption,

teams decode the German signals,

then feed the intelligent to the Royal Air Force fighter command.

Bletchley Park is absolutely vital

for the British defence in the Battle of Britain.

Why?

Because it reveals the Luftwaffe order of battle.

So you can see who's going where, when.

And better still, it also reveals that the Germans have

these direction-finding beams for their aircraft.

And if you can intercept those beams,

you know where the aircraft are going in advance.

And you could therefore defend those targets far more adequately.

It also reveals the true extent

of German aircraft losses.

Now, that's a really important piece of information for the RAF

because they know that the Germans are getting hammered.

So it is absolutely vital.

The work at Bletchley Park is crucial

to the RAF's victory in the Battle of Britain.

Hitler indefinitely postpones the invasion.

The scope and scale of the code-breaking operation

expands with its success.

The initial stage is the collection

of the signals themselves

at interception sites dotted

all around the UK and overseas.

Any signals that are encrypted would be relayed

via teleprinter or via a dispatch rider

who would relay the material back to Bletchley Park.

Now, Alan Turing's Bombe machine starts

the key part of your encryption process.

Then, specialised teams will finalise that

and decrypt that message.

But it's in German now. So now you've got translators

who are working to translate the message into English.

We needed linguists.

We needed to people who were good

at clerical administrative tasks and typing,

which is why the site mushroomed in terms of numbers and scale.

Finally, you need to analyse the message

and send it out to commanders in the field,

so that they can put it into use.

This was to produce intelligence for all theatres of war.

It wasn't just producing material for Europe.

It was producing intelligence

from North Africa, the Middle East, the Far East.

This was a global war, and it needed global intelligence.

The Enigma signals intelligence generated

by Bletchley Park is given a name -

"ULTRA" for "ultra secret."

Winston Churchill is its biggest champion.

He has long-believed

that intelligence will help the Allies win the war.

For a general or a politician, to be able to read

the innermost thoughts of your enemy is like a superpower.

Churchill would look at these intelligence reports in his bath,

in his bedroom, out in the garden.

He wanted to see the raw intelligence.

He was fascinated by it.

And Churchill could see that, in Bletchley Park,

he had a potentially war-winning tool.

He made sure they had the resources they needed.

He made sure they had access to him. He said that they could get

in touch with him any hour of the day,

no matter what.

Churchill understands

how important military intelligence can be.

He was Home Secretary and led MI5,

Britain's domestic Intelligence Service.

Heil eurem Fuehrer!

Heil! Heil, Fuehrer!

Hitler, on the other hand, has long been sceptical

of the usefulness of military intelligence.

I don't think Hitler values intelligence

in the same way that Churchill did.

Hitler is a guy who believes in his instincts.

He believes in his vision.

Hitler is so caught

in his own ideological thinking

that he rejects out of hand intelligence

that doesn't go along with his worldview.

He doesn't rely on it all that much.

German military intelligence - the Abwehr -

is led by Admiral Wilhelm Canaris.

Canaris has planned German espionage campaigns all over the world,

including in the United States.

By all accounts, Hitler is largely very impressed by him.

Canaris is very sophisticated.

He's really on top of his job.

He's terrifically well informed.

And he has some good ideas.

But Canaris is a realist,

and the Abwehr's intelligence is often too candid for the Fuehrer.

He keeps coming up with reports that suggest

that a war with Britain would be a long, hard war,

that a war with the United States would be unwinnable,

that even a war with the Soviet Union would be much more difficult.

Nobody wants to hear from pessimists right now,

especially an invincible Hitler at the height of his power.

Hitler believed predominantly in military might.

The great German military machine.

And to be honest, he has great reason

to believe in the might of his army because it's achieving things

that have never been achieved before.

In Britain, Churchill doesn't have

the military resources

to attack Germany on the ground.

So he creates the Special Operations Executive,

which launches espionage and sabotage campaigns

throughout Nazi-occupied Europe.

But Churchill knows that this is not enough.

He needs an ally.

He needs the United States.

After months of Luftwaffe attacks,

Prime Minister Winston Churchill is determined

to persuade the United States to enter the War.

Without America as an Ally,

he fears Hitler will defeat Great Britain

and absorb the British Empire.

One way for Churchill to gain American confidence and support...

...is to share critical intelligence and information

with the United States.

Churchill is so desperate to get the Americans into the War

that he does really anything he can to woo them.

He wants the Americans to be impressed.

He wants the Americans to enter this alliance,

come into the War with confidence.

And what could be more persuasive

than showing off to the Americans,

telling them that you're on the way to building

a pretty complete picture of everything your enemy is doing

and thinking and saying in private.

That's an Ally you want to have.

In February 1941,

the first American delegation comes to Bletchley Park.

Winston Churchill gives authorisation.

From then...

the American and British Partnership really started

to move at pace; it blossomed.

Intelligence officers from both countries work together

throughout 1941.

But, in December, when Japan attacks Pearl Harbor...

...cooperation evolves into alliance.

America is now at war with Japan.

And days later... with Germany.

America has almost no Intelligence Service

before we enter the War.

So there's Army and Navy code-breakers.

But there's no equivalent

of the British Foreign Intelligence Service.

American Intelligence is like a cottage industry.

You know, it's at a pre-industrial stage

before Pearl Harbor occurs.

Now the United States works with Britain to establish the OSS,

the Office of Strategic Services.

But as the Americans enter the War,

the Germans still control a large portion of Soviet territory.

And the Japanese continue

to sweep through the Pacific and Southeast Asia.

By 1942... you have an unprecedented...

trans-Atlantic collaboration,

intelligence sharing on every level.

The Americans are in every department

in Bletchley Park working alongside Britain.

So this is a really significant, enduring partnership.

ULTRA's success gives the Allies an advantage -

especially in the crucial Battle of the North Atlantic.

It reveals the location of Nazi U-boats,

allowing Allied navies to avoid German Wolf Packs,

and safely re-route the all-important convoys.

It has an incredible impact on the Battle of the Atlantic.

As a matter of fact, it swings the entire battle

in the Allies' favour.

Despite this, most of the German High Command

still believe the Enigma codes are unbreakable.

But Admiral Karl Donitz,

the Commander of the Nazi U-boat fleet,

cannot understand how Allied ships keep sailing around his submarines.

Admiral Donitz is by far

the most security-obsessed military leader

in the German war machine.

And he sniffed out the fact

that we're rerouting our convoys.

Admiral Donitz orders an examination

into the integrity of the Enigma codes and ciphers.

His intelligence officers insist

that the system is impregnable.

They argue that the Allies are using radar to track U-boats.

Or that there are spies in the German Navy.

They launch investigations to identify possible traitors.

The Germans are so convinced that it is unbreakable

that they don't see what's going on,

even if it stares them into the face.

They never try to prove that it has been broken.

They always try to prove that it cannot be broken,

meaning that they always end up

at their preferred answer -

everything is fine.

In February 1942,

Donitz orders a security upgrade to the Enigma machine.

A fourth rotor is added,

strengthening the encryption even further.

In 1942,

the German U-boat flotillas changed

from the M3 to the M4 Enigma, adding a fourth rotor,

which added a huge layer of complexity to attacking the cipher.

Basically, it takes the odds

of 150 million-million-million to one from the three-rotor

up to an unfathomable...

92 septillion to one shot.

This addition is a major setback

for Bletchley Park in the North Atlantic.

It's almost like the light's going out

on a grid of an electrical pattern.

You can't find submarines anymore.

Once again, German U-boats pose

a grave threat to Allied shipping.

Intelligence officers at Bletchley Park are no longer able

to decrypt German naval signals.

To utilise ULTRA in the Battle of the Atlantic again,

the British will attempt to seize the codebooks

the Germans use to set their Enigma machines.

The Allies are on the verge of losing the Battle of the Atlantic.

The first half of 1942 is once again referred to

as the "Happy Time" by German U-boat commanders.

One thing that can help the Allies is

to restart ULTRA in the Atlantic.

But they need to decrypt the new Enigma messages.

This code material is absolutely priceless

for the code-breakers of Bletchley Park.

It was used to set up the machine.

It shows how it's supposed to be configured

for every single day of every single month.

The British launch secret raids

to extract any intelligence they can find

on German submarines, ships, and military facilities,

including Enigma codebooks.

They call the raids "pinch operations."

"Pinch" is British slang for "stealing."

British Intelligence Officer Lieutenant Commander Ian Fleming

helps to coordinate pinch operations.

Ian Fleming ends up

at the Department of Naval Intelligence almost by accident.

He's got no experience in intelligence work,

but he very quickly finds his feet.

He has this gift for analysis

and weighing up intelligence options.

Fleming, who later writes the James Bond novels,

plans a pinch operation in connection with an Allied raid.

Operation Jubilee will be a large amphibious landing,

essentially a dress-rehearsal for the expected invasion of Europe.

It involves 1,000 aircraft

and more than 230 ships.

Their target is the heavily fortified French port of Dieppe.

The Allies know they're going to have to stage

a landing in Western Europe

in order to win the war against Hitler's Germany -

it's a test to see if you can seize a port.

At the centre of this was the Royal Marine Commando,

which were a British unit,

but the vast majority were Canadian infantry.

And then, of course, this was the debut

of the United States of America.

There were 50 United States Rangers

that were going to go into combat on European soil

in the Second World War for the first time.

Lieutenant Commander Fleming and a small team

called 30 Assault Unit

are part of the raiding force.

They have a specific objective.

With Fleming coordinating aboard ship,

30 AU will attempt to enter

the German Navy's regional headquarters

and a nearby supply depot.

Both will likely contain codebooks for the new Enigma machines.

From a pinch perspective...

what is really important about Dieppe is

that they have all these code books waiting to be distributed,

not only for the next month, but months in advance.

But after initial success,

the landing at Dieppe disintegrates.

It is absolutely Hell.

You've got to run up this beach, carrying all your kit and a rifle.

And of course, you've got German machine guns,

mortars, artillery, you name it, firing at you.

It becomes an absolute slaughter.

Over half of the Allied forces at Dieppe are killed,

wounded, or captured.

Most of 30 Assault Unit's men are killed.

At the end of the day, they come away with nothing,

despite all the bloodshed.

The raid on Dieppe is a failure from every angle.

But the British still need German codebooks

and intelligence to revive ULTRA.

Allied ships are ordered to make seizing German intelligence

a part of every mission, when possible.

In the fall of 1942,

HMS Petard is one of a small destroyer groups

sent to hunt Nazi U-Boats.

When they locate U-559,

they launch depth charges...

...and force it to the surface.

The U-Boat crew abandon their submarine.

It was sinking slowly.

And this gives the opportunity for the crew of HMS Petard

to actually board the U-boat

and try to pinch and capture the material

from the sinking U-boat as it's going down.

Three men rush inside -

Lieutenant Tony Fasson,

Able Seaman Colin Grazier,

and a 16-year-old canteen assistant, Tommy Brown.

They're down there working with flashlights,

ransacking the place, looking for anything.

But it's a race against time

because the U-boat is starting to fill with water.

The three British sailors have minutes

to find useful intelligence.

Three British sailors desperately search

a crippled U-Boat as it begins to sink.

What they find could help win the War.

They go down to the signals office.

Then, they go into the captain's cabin, and sure enough,

find the material and a whole lot of it.

These guys, freezing cold,

petrified, are below deck

feeding crucial, rich signals intelligence -

these cipher books -

up the conning tower.

Almost like a conveyor belt, one guy to another, to another.

Suddenly, the submarine takes on

this huge rush of water...

...the pressure of which pushes the teenager Tommy

out of the conning tower like a cork from a bottle.

But tragically, it kills the two men

who have done this VITAL work below deck.

They're actually trapped... as the water starts to come in,

and they give their lives to affect the pinch operation,

which changes the course of the intelligence war.

The courage of these three British sailors means

Bletchley Park can once again decode

the German navy's Enigma messages.

But now, the code-breakers become victims of their own success.

The number of enemy signals they intercept

and decode grows so rapidly

that the Bombe machines can no longer handle

the sheer volume of material fed into them.

The Allies need to process military intelligence

on an industrial scale.

So, Great Britain turns to its Ally:

the United States.

We send our most precious asset...

the other side of the Atlantic; we send Alan Turing to America.

In the winter of 1942,

Turing meets Joe Desch, an electrical engineer

at the National Cash Register Company in Dayton, Ohio.

As a result, the Bombe machines evolve into an electrical,

as well as a mechanical, weapon against the Third Reich.

Desch's machine is transformative technology.

He's invented the first...

electronic computer memory.

The new machines are six times faster...

...and are mass-produced in the hundreds.

By decrypting messages at such speed and scale...

...the Allies are able to access key German information

and, in combination with a mosaic of intelligence operations -

deception, espionage, and sabotage -

they can corroborate that their secret war is working.

In the Spring of 1943,

Allied Forces - under the leadership of Dwight Eisenhower -

have forced the German and Italian Armies out of North Africa.

The Allies' plan is to next invade the island of Sicily.

The only real problem with Sicily is

that it's somewhat of an obvious target.

If you're looking at a map,

Sicily is the first big island.

The Allies believe it's necessary to spread

a little disinformation around,

make Hitler and the German planners think

the landing is coming somewhere else,

perhaps in the Balkan Peninsula to the east.

Anywhere but Sicily.

In February 1943,

Ian Fleming, and other British intelligence officers,

formulate a plan.

It emerges from a list of ideas

known as "The Trout Memo."

The Trout Memo is so-called

because it uses fly fishing

as a kind of analogy

for conducting deception operations

against the Germans.

Now, it's widely believed that this was largely written by Ian Fleming.

It's very much in his style.

And it shows that very imaginative thinking

for which he's later going to be absolutely renowned, of course.

Most of the suggestions in it are pretty far-fetched.

But there's one that actually does catch the eye,

and that's this idea of putting false information on a corpse,

and then allowing it to be discovered by the enemy.

Intelligence officers believe

this could be a way to feed the Germans false plans

for an Allied invasion of The Balkans.

It's a fiendish and dastardly idea.

If the Germans believe the false documents,

they will have the wrong idea

of what the Allies are going to get up to.

The British name the plan "Operation Mincemeat"

and present it to Eisenhower.

Eisenhower's buy-in is required

because Eisenhower is essentially the theatre commander in the area.

It's also indicative of American trust

in this particular operation.

With Eisenhower's approval,

British Intelligence moves to the next stage.

They find the corpse of a homeless man in Britain,

and they build an entire story for him.

A lifetime that he never actually enjoyed in person.

They give him a uniform. They give him a career.

They put identity cards in his wallet.

They give him pictures of an imaginary girlfriend,

the lovely Pam.

He becomes Major Martin, British Intelligence Officer.

The final step is to give Major Martin a briefcase

containing fake plans for an Allied invasion of The Balkans.

The Allies must now get Major Martin's documents

into the hands of Germany's intelligence chief,

Admiral Canaris.

In the early hours of April 30th, 1943,

a British submarine drops a corpse

dressed in the uniform of a Royal Marine

into the sea off the west coast of Spain.

A briefcase is attached to the corpse by a security chain.

The British hope the documents inside the case...

will make their way to Adolf Hitler in Berlin.

They've chosen Francisco Franco's Spain

because they suspect the Spanish will

pass the information to the Germans.

The British know the German Intelligence Agencies,

especially the Abwehr under Wilhelm Canaris,

have a really good relationship with the Spanish.

So, this is a far more clever and subtle way

of getting deception information into German hands.

Rather than just dumping it off the coast of Germany...

...put it off the coast of Spain,

and you've got a more plausible way

of that information coming through the pipeline.

A Spanish fisherman finds the body.

Soldiers guarding the coast take it to Spanish Navy officers,

who tell German Intelligence agents in Spain

what they've found.

But signals decrypted at Bletchley Park

show the Germans are sceptical.

The German agents in Spain simply don't take the bait.

Back in British intelligence,

there's this terrible panic

that Mincemeat is going to fail.

You know, it's just going to be ignored.

To ignite interest in Major Martin,

British Intelligence writes a letter to the Spanish authorities,

demanding the return of the briefcase

and the document inside.

They want to make it look

as though the British are deeply worried,

as though, you know, this really is...

a proper officer with real plans on him.

This is a really daring gambit

because it may seem too obvious.

But, actually, the British are lucky.

What that does is to get the local German agents

to get hold of the plans

that "Major Martin" is carrying,

they photograph them,

and they send those photographs

back to their boss in Berlin:

Wilhelm Canaris.

Canaris is interested.

He examines the plans for days...

then hands them to Hitler.

The Fuhrer already suspects

the Allies will attack through the Balkans,

so he's inclined to believe the information.

But propaganda chief Josef Goebbels is wary.

Goebbels is smart, and Goebbels, after all,

is, you know, the Minister for Propaganda, for Lies.

He knows what it means to deceive people.

He thinks it's a bluff.

The information Canaris gives Hitler confirms his instinct.

Two days later...

Bletchley Park decodes a message.

The Germans are moving troops toward the Balkans.

Operation Mincemeat is working.

The work of Bletchley Park feeds

into a deception campaign like this in a really important way.

ULTRA allows you to understand

whether your enemy is...

buying the deception you're trying to sell.

We can see,

thanks to our Bletchley decryptions,

that Hitler is pulling Panzer units

to the Balkans, to Greece...

directly because of one dead corpse

that's left floating off the shores of Spain.

Two months later, the Allies land in Sicily

and capture the island more quickly than anticipated.

The depleted number of German defenders is

a critical part of their success.

This is one of the most successful

intelligence operations of the Second World War.

Canaris's reputation begins to suffer

after Operation Mincemeat.

As the War goes on, after that,

Canaris will be more and more...

disliked and distrusted by Hitler and the other elites of the regime.

- In 1944,

the Third Reich abolishes the Abwehr,

and Canaris is accused of being involved in a plot to kill Hitler.

A year later, he's hanged -

just weeks before the end of World War Two.

Accurate intelligence is critical to military victory.

But ultimately, the outcome is determined by combat.

The decisive battle of the war against Nazi Germany

is about to be fought -

at terrible cost -

in a strategically-important

Soviet city on the Volga river. Subtitles by Sky Access Services