It was the first time that Benny had seen the outline of the plane. The scene reminded her almost of a Viking funeral pyre. Then, every pound of explosive in the bomb bay detonated simultaneously. There was a hammer-blow deep inside the Earth, a sound so loud it lifted them off their feet and shattered every pane of gla.s.s for two miles in every direction. A column of fire hurtled five hundred feet in the air, and scooped a crater twenty feet deep in the soft soil of St James's Park. The lake was seething and boiling and tiny chunks of metal and earth began clattering back down to the ground like rain. A fragment of the wing sliced into the ground where Chris had just been standing. There were shouts from across the park. Fire-watchers.

The Doctor smiled rather smugly.

'We have to be going.' He checked his watch. 'Where's Roz got to?'

'She's got her own unfinished business,' Chris whispered.

'I'll go and collect her. You've got a key to the TARDIS, let Benny in.'

On the other side of the park, George Reed held Roz close.

Together they watched the fire-fighters as they milled around the burning wreckage. It was as bright as day here, brighter. In the firelight, Roz's skin was the colour of burnt amber.

The Doctor announced his presence by clearing his throat. Reed turned to see who it was. The Doctor kept a little way back.

'We won,' Reed said simply. There were tears in his eyes. 'Doctor, Roz has told me who you are, told me that you aren't von Wer. Thank you for what you did tonight.'

The Doctor bowed his head to accept Reed's appreciation. It's time to get going, Roz.' He looked her straight in the eye. 'Or do you want to stay?'

Reed broke his embrace and stepped back, but Roz caught the officer's hand. 'Yes.'

The Doctor smiled. 'That simple?'

'No.' She hesitated and turned to Reed who, outwardly at least, remained impa.s.sive. 'It's so beautiful here. If it wasn't for the war, it would be so peaceful.'

The Doctor chuckled. Roz squeezed Reed's hand.

'You know what I mean,' she snapped.

'Of course I do. I remember the very first time I visited Earth: Paris during the French Revolution. There was so much promise there, a sense that anything and everything was possible. I walked the dirty, wine-soaked streets with my granddaughter, and I realized that the old order could be swept away, that people could be happy. It was a feeling I'd never had before: elation at the sound of empires falling.'

'The French Revolution ended in chaos, Doctor; thousands died,' Reed noted. He took the little man and his story in his stride.

'Would you like to come with us, George? There's always room for one more. You could see the sights, fight epic battles.'

No, Doctor. There's a war to be fought and won here.'

The little man nodded, as if it was the answer he had expected. 'Is it your war, too, Roz?' the Doctor asked. 'It's your decision. I'll be back at the TARDIS.' He disappeared into the night. Roz looked up at the clouds again, saw them as flying cities, ablaze. Around her she could hear shouting and the distinctive pulsing chirp of energy hand-guns. Elation.

Chaos.

'I'm sorry, George.'

Reed managed a smile. 'I know you are. I'll try to keep a stiff upper lip, though, yes?'

'We might meet again. It is possible.'

'We'll meet again some sunny day?'

Roz glanced up at the clouds. 'Then it won't be in England.'

George chuckled, then a thought struck him. 'I almost forgot.' He held out the green bag he was carrying. Roz peered inside, and George continued, 'It's a fur coat. Silver fox, to match your hair. It cost me quite a few coupons, not to mention a few favours, but you were always complaining about how cold it was and -'

Roz kissed him.

'You'll still wear the ring, won't you?'

Roz nodded, holding up the emerald for his inspection.

'Of course, if that's what you want.'

George kissed her cheek, tasting a salty tear there. Roz grabbed the scruff of his neck and pulled him even closer.

Finally, she drew back. 'I better get going.' Roz straightened, tugging her uniform jacket back into shape.

'Goodbye.'

The Doctor's hand hovered over the dematerialization control.

Benny tapped him on the shoulder. He turned. She shook her head. The Doctor withdrew his hand.

The door swung open and Forrester stepped inside. The door closed behind her and she handed the Doctor back his TARDIS key. Chris was grinning, so was Benny. Wolsey brushed against Roz's leg.

The Doctor's hand tapped once at the console and the crystalline column at the centre began rising and falling.

Once he was sure they were in flight, he turned to Benny.

'I'm sorry.'

Benny stood impa.s.sively. The Doctor looked down sadly, and shuffled out of the control room.

When he was gone, she smiled. 'That's all I wanted to hear.'

Roz glanced nervously between Chris and the console.

'Where are we headed?'

'Don't worry, the TARDIS won't crash into anything. It's quite capable of flying itself,' Chris a.s.sured her.

'That's not what I asked.' She shooed Wolsey away from her Harrods bag.

Chris scanned the readout. 'Canterbury. Twentyfirst-century time zone.'

'They will have central heating there, though, won't they?' Roz asked Benny hopefully.

The archaeologist yawned. 'Central heating, electric blankets and global warming,' she a.s.sured Roz. 'I'm off to my room to write up my diary. It looks like we could all catch up on our sleep. Especially you, Captain Forrester.' She giggled as she left.

'What did she mean by that? Was there an air-raid last night that kept you awake?' Chris asked curiously. Roz just scowled.

The Doctor sat alone in the centre of the Infinity Chamber, remembering. Above him holographic stars twinkled far away in a fake night sky.

In another time and another place, the Doctor sipped at his lemonade. He was sitting outside, on the balcony of the Grand Imperial Hotel, watching the moon and stars. It was cool, now. Earlier, Mel and Emil had been the centre of attention on the dance floor, dancing a mean tango. They were sitting in a darkened corner of the ballroom now, and the Doctor knew enough about human nature to give them some privacy.

Was Mel leaving him so soon? She wouldn't stay with him forever, the Doctor knew that. Then, the last link with his past self would be severed and he would have to make the first move in a new game. There was so much to do, so much unfinished business. Wolves and ravens were gathering at the fringe of the battlefield. Long-forgotten forces from the ancient past and the distant future had returned, and he could feel their eyes watching him.

The Doctor angled his straw and sucked up the last dregs of his lemonade.

There was a distinctive scream from inside the hotel, and Mel came running onto the balcony, hoisting up her skirt so that she could run all the faster. The Doctor was already standing. 'Mel, what's the matter?'

'Doctor, Emil's a German.'

The Doctor furrowed his brow, baffled. 'Well, yes.'

'It's 1936. We'll be at war soon!' she reminded him.

'We? I'm not human, let alone English, and you won't even be born for another thirty years.'

'Twenty-eight. That's not the point. My grandfather died in the war.'

'Hartung didn't kill him.'

'But he's a n.a.z.i, he just told me. He's a Party member.'

'Most Germans were in the 'thirties. Your ancestors supported slavery, workhouses, fox-hunting and burning witches at the stake. Most of them were nice people. Emil's a nice person.'

Mel shot him an accusing look. 'I've got to get out of here.'

The Doctor smiled thinly. 'I know.'

The rocket arced over the forest high into the clear blue sky.

It was Christmas Eve 1942. Generalmajor Oskar Steinmann watched the vapour trail rend the sky in half.

The future was unfolding around him. He'd memorized the chapter in Summerfield's book, watched each one of its predictions come true in turn. His warnings had gone unheeded, his actions had made no effect. 24/12/42 - The 24/12/42 - The first test of the 'flying bomb' at Peenemunde first test of the 'flying bomb' at Peenemunde.

It had all changed in the last eighteen months. The attack on Russia had started only a couple of months after the destruction of the Hartung Project. Britain was undefeated, and Germany suddenly found itself fighting wars on two fronts, just as it had in the Great War. At first it had seemed to make sense - there were untold resources in Russia: land, slaves, oil, grain, metals. On the first day of the attack, the Luftwaffe had wreaked havoc - destroying nearly two thousand Russian planes, wiping out an entire country's airforce. German forces advanced forty miles into Russia every day, capturing more Soviet soldiers than they were able to process, moving so fast that the Wehrmacht couldn't establish their supply lines fast enough. The Baltic States fell easily. At the great battles of Bialystock, Kiev and Vyazma-Briansk, the Germans captured over two million soldiers - more men than were in the entire British Army. Soon the Wehrmacht had advanced one thousand miles into Russia, along a two-thousand-mile front. Joyfully, the radio announced success after success. Soon the propagandists had been forced to tone down reports of the victories because no one believed them.

And then, within sight of Moscow, the first snow fell, and the German army ground to a halt. The Russians, prepared for the conditions, fighting for their own land, drove the Germans back. Steinmann had been transferred from Guernsey at that time to sh.o.r.e up the Eastern Front. His Luftwaffe squadrons had managed to halt the advance of the Russian tanks, fortified and supplied strategic towns, blocked Russian supply routes. The Germans, though, had been forced to all but abandon bombing raids against the United Kingdom and all plans to invade England were shelved.

The character of the war changed at that moment, became defensive, vindictive. Suddenly, Berlin became worried. There were witch-hunts. A lot of good officers were punished, civilian dissidents were ruthlessly purged. No one could question a command now, however insane it seemed.

Any talk that Germany might be defeated was treason.

Where was the n.o.bility in killing unarmed women and children, whatever race they might be?

And then the unthinkable happened. America entered the war, adding its ma.s.sive resources to the British and Soviet efforts. Suddenly, it was Germany that stood alone. It was around that time that Steinmann had been called back to develop wunderwaffen here. He was working with many of the team that had a.s.sisted Hartung; they had pieced together what they could of his discoveries. But it was a hopeless task. 23/4/45 - Russians on outskirts of Berlin; 28/4/45 - 23/4/45 - Russians on outskirts of Berlin; 28/4/45 - Mussolini executed; 30/4/45 - Suicide of - 'Impressive, isn't it, sir?'

Steinmann glanced over to the seventeen-year-old Unteroffizier. 'It is a magnificent achievement, but won't win us the war.'

'It will strike terror into our enemies and -'

'It is a psychological weapon, that is all. It is still a year and half from any practical application, and will never be able to carry the same explosive payload of even a light conventional bomber.'

'That is defeatist talk, sir. This is our only hope of beating the British - you are saying that we will be defeated.'

'Perhaps I am.'

'Traitor!' the soldier shouted.

'We all have our part to play in history, soldier. But remember that we can't all be on the winning side.'

The Unteroffizier turned away, disgusted by what he had heard. Steinmann stood for a minute in silence, staring at the vapour trail, remembering the future, remembering all the millions who would die. Then he too turned away.

Glossary

Banzai - j.a.panese battle-cry, literal meaning 'ten thousand years'. - j.a.panese battle-cry, literal meaning 'ten thousand years'.

Chain Home - The British south coast radar stations. - The British south coast radar stations.