Chris watched the limousine hurtle past, catching a glimpse of the pa.s.senger in the back seat. No, it couldn't be...

'Where the h.e.l.l were you?'

'Language, Lieutenant Reed, there's a lady present. Not only that, she outranks you.' Forrester was infuriatingly calm, and she wasn't even slightly defensive.

'Ma'am, do you have the photographs?'

'They are back in the safe.' George sighed with relief, but Forrester continued, 'I made copies.'

'Copies? Roz, Kendrick will have us shot! That isn't a figure of speech.' Watching Forrester now, though, Reed realized that he trusted her. Roz sensed this, and smiled rea.s.suringly.

'Invite me out for lunch, George.'

'You're invited. We'll go to the Salted Almond on Piccadilly. I was going to ask you this morning, but you weren't there. What on Earth have you got planned?'

'I'll tell you over lunch.'

Wolff called for her.

Kitzel put down the magazine she was reading, and hurried over to the door as it opened. Wolff strode out of the room, wiping his hands on a towel.

'Attend to the prisoner, please, Nurse Kitzel, she seems to have broken her hand. I will be back shortly.'

Kitzel stepped warily into the cell. The room smelt of sweat and urine. Fraulein Summerfield sat crying. Her wrists and ankles were still secured to the chair with adhesive tape.

Her right hand was limp. Kitzel examined it, wincing as she saw the swelling.

'D-Do you think this is fair?' the prisoner asked weakly.

There was no sign of her earlier defiance.

No, thought Kitzel. 'Yes,' she said.

'You think that I deserve this?' The prisoner managed to sound astonished.

No one deserves to be treated like this. 'Yes, I do.

Please keep still.'

She began to strap a splint around the prisoner's hand. It must have hurt, but the prisoner did not acknowledge the fact. The prisoner tried to cough, but her throat was too dry.

'You're an evil little b.i.t.c.h,' Summerfield finally managed.

'I'm a nurse, you're a murderess. Work out from that who's evil.' Kitzel wrapped a bandage firmly around the wounded hand.

'Look at me!' For the first time, Kitzel looked into the prisoner's face. Her right eye was black and swollen, there was a nasty cut on her forehead. Wolff had not given permission to treat these injuries. Kitzel looked away.

'There is no permanent damage,' Kitzel said, attempting to sound rea.s.suring. 'I am done here.'

'Please don't go,' pleaded the prisoner, attempting to grab Kitzel's arm with her good hand. It was easy to brush her aside. It was even easier to leave the cell.

The Mercedes came to a halt outside the gates, and the driver turned off the engine. Two of the Germans manning the sentry post came forward. One meticulously checked the car, including underneath the cha.s.sis and inside the boot.

The second checked the driver and the Doctor himself. He scrutinized the driver's ident.i.ty papers, and already had a photograph of the Doctor attached to his clipboard, which he carefully compared to the man in the back seat.

'You may get out,' he barked finally.

The Doctor said his farewells to the driver and stepped from the car. The first guard had finished his scrutiny of the limousine, now he performed a quick body search on the Doctor. His pockets had been virtually emptied at Granville, although the guard managed to discover an apple core that had infiltrated the Doctor's jacket since then. The guard tossed it away, then nodded to his counterpart.

'Thank you, driver.' The engine roared into life again, the car executed a three-point turn and then sped off back to Granville. The Doctor glanced at the ground, trying to look casual. There were vehicle tracks in the mud leading into the base: motorbikes mostly, one or two cars. Nothing heavier had gone into the base, as far as he could see. A couple of armoured personnel carriers had arrived here, but the troops had been dropped off at the gate, as he had been.

'Open the gate.' A couple of guards scurried forward from just inside the perimeter and pulled the heavy gates back.

'Do I not get chauffeured in?' the Doctor asked cheekily.

The guard ignored him. A young Leutnant was waiting for the Doctor inside the gate. He was about twentyfive, with cropped black hair. The officer saluted him. The Doctor didn't return the compliment.

'Herr Doktor, I am Leutnant Keller. Will you follow me, please?' Behind them, the gates were already being pulled shut.

'Where are we going?'

'Just to the end of this track.'

The Doctor peered into the distance. The dirt track carried on for two hundred yards or so, before curving around a hillock. Their destination was obscured by this, and by a cl.u.s.ter of pine trees in the middle distance. It was just possible to hear running water down there. A herd of cows stood rigidly thirty feet from them.

'This does not look like a military installation.'

'No.' Keller chuckled conspiratorially. They continued to walk along the track. The Doctor watched a couple of swallows chase each other towards the trees. He and Keller had walked past the cows. It seemed strangely in keeping with n.a.z.i mentality to surround a nature walk with a ten-foot electric fence, but he fancied that there was more to this place than met the eye. There was something very odd, something he couldn't quite put his finger on. The Doctor glanced back at the herd of cows.

'Mind the cowpats,' joked the Leutnant. There weren't any. It was hardly the best joke in the world, and merely served to distract him from his train of thought. They were coming up towards the pine trees. A couple of guards were posted up in the tree, and they peered through the slits in the branches down at the Doctor and his escort making their way up the track. The couple in the next tree were keenly watching the sky. The Doctor fixed his attention ahead. The path had led to the end of a small valley. Strangely, the stream he had heard cut across it. He scuffed his shoe on the gra.s.s as it suddenly hardened.

Hang on.

The Doctor spun back to look at the pine trees. The concrete pine trees.

The Leutnant was laughing. 'It's good, isn't it?'

The Doctor was pretty sure that his expression must have betrayed something of his surprise. The trees were guard posts, shaped and painted to look like pine trees.

They'd fooled him from fifteen feet away. Now he knew what he was looking for, he could see how there was a metal ladder bolted to the 'trunk' of the tree which led up inside the 'cone'. Twentyfive feet in the air, foot-wide slits allowed almost a 360-degree field of vision. Two German soldiers were posted in each 'tree'. How odd.

The Doctor bent down, rubbing the ground. It wasn't gra.s.s at all, it was tarmac.

'Green tarmac,' the Doctor mused. Keller was looking very pleased with himself. The Doctor twirled around.

'I'm standing in the middle of an invisible airbase,' he declared.

It was incredibly clever. These hillocks were almost certainly buildings of some kind, covered over with earth, just like Saxon burial mounds. Judging from the size of some of them, over a hundred feet square, they could only be aircraft hangars. There were smaller protrusions - fuel tanks? The barracks and laboratories were probably below ground: they would be sheltered from aerial bombardment down there, as well as being totally camouflaged. If they were really testing jet engines here, then it would be ideal soundproofing, too, as long as it was properly ventilated. What the Doctor had thought was a cottage was actually a control tower. An aircraft control tower with a thatched roof.

'This installation doesn't look like anything of the sort from the air,' the Leutnant was saying. 'Normally, everything at an airstrip is laid out logically and neatly. We've broken up all those lines. Everything is either covered up or painted.

We've left as much natural vegetation in place as we could, and supplemented it with the odd fake bush and concrete tree.'

'It's invisible from the air.'

'As you have discovered, it would be invisible from the ground if it wasn't for the fence. We need that, though, to stop the locals stumbling upon us. Again, the barrier is too thin to appear on aerial photographs.'

'You've deliberately left the route here as a dirt track.'

'It carries on out the other side of the base and leads to the sea eventually. The track runs straight across the runway.'

'The -?' The Doctor looked around. Yes, of course, the valley was a runway, a runway painted a mottled green. It was about two hundred feet long. He quickly made a series of calculations.

'You've been to Guernsey, yes? Did you see the Mirus batteries? We put some gun emplacements on the cliff tops there, and painted them to look like cottages. Crude compared to this. If you know about them, they are pretty easy to spot. The trick is not to tell the enemy about them.'

'Indeed,' murmured the Doctor. 'Just one thing. Why do you keep a herd of cows inside the perimeter? It's a nice touch, but it could be dangerous: you'd have to keep them from wandering all over the runway and - ' Keller cut him short.

'Herr Doktor, the cows are concrete. Did you not realize?'

The Doctor shut up.

This time last year, the Salted Almond on the Trocadero had got into trouble for an advertis.e.m.e.nt it had placed in a couple of the national papers. Under the caption 'All Set For Blitz-Leave', there had been a picture of a dinner-jacketed waiter ushering a couple of bright young things to their table. In the foreground, a navy admiral entertained a pretty young woman in an elaborate ballgown and hat. In the background, a band played, and a beautiful dancer danced. The advertis.e.m.e.nt went on to offer an escape from the Blitz, a place where the privileged could while away the hours, safe from German bombs. At a time when the government were desperately trying to instil a sense of national unity and urging restraint, this picture summed up the fact that, for some, there had been few real sacrifices. The poor huddled together in the Tube stations, without even basic sanitation, let alone any real organization; the rich dined in top restaurants, and retreated to their country homes when night fell.

The advertis.e.m.e.nt had been withdrawn, but as Reed and Forrester entered the restaurant it was clear that down here nothing much had changed. This was still a place for the Establishment to shut out the war, and the scene was just the same as that shown in the picture. As the door was closed behind her, Roz realized that she had just stepped into another universe. Who needs a TARDIS? All you ever need is money. Her parents lived like this, barricaded in their palaces, blaming the poor for the problems of the galaxy.

The waiter showed them to their reserved seats. Roz had grown used to the sideways glances that a black woman got on the street in this period. Here, the people stared. She looked back, hoping to convey just a fraction of the moral superiority that she felt. A few looked down at their plates, apparently ashamed. Mission accomplished.

Reed pulled a chair back for Roz, then sat down opposite her. He'd lived all his life in places like this.

'All right, what is going on?' His face wasn't really built for anger.

'It's lovely and warm in here, isn't it?'

'Tell me, Roz.' George sounded genuinely angry. Roz didn't want to push him too far. She produced the duplicate photographs that she had prepared using the facilities in the TARDIS. She had been careful to annotate everything by hand to make it look as if it was all her own work. There would be quite enough questions without the distraction of having to explain how she had managed to invent the computer.

'London, on the morning of March the second. That was the night you and Chris met me at that police box. The night before the library was. .h.i.t, yes?'

Reed agreed, adding that Paddington and St Kit's hospital had also been hit that night.

'You said the Germans were lucky, remember, and that a lot of the planes came from the Channel Islands,' said Roz.

'Now, what would you say if I told you that the spotters and radar both said that there weren't many planes in the sky compared with other nights?'

'I would remind you that Kendrick had taken us off raid a.n.a.lysis because we weren't getting anywhere and told us to look out for von Wer.'

'Von Wer isn't a problem.'

'And how can you make that judgement?'

A mental image of the Doctor's gormless grin swam across Roz's consciousness. 'I just know, that's all,' she concluded.

Reed sighed.

'Look, Lieutenant, trust me on that one. Now, logically, if, on only one night, less planes cause more hits, something odd is going on.'

'You think the Germans used the superbomber?'

'I know they did. Now, I got up early this morning and plotted out what happened on that night. This.'

She handed him the a.n.a.lysis prepared by the TARDIS.

Again, she had painstakingly copied it out in her own handwriting, rather than just making a hard copy. From the photographs, the computer had known where and when the damage took place. It was relatively simple for the computer to work out the yield of each bomb by measuring the damage each one caused. Knowing which planes were capable of dropping which bombs, and comparing this with radar data, it had been possible to match each bomb to each plane. In a matter of seconds, the computer had plotted the course of an eight-hour air-raid. Now, not even the TARDIS computer was perfect, especially when dealing with this sort of chaos. It had rejected its own first guess, because it hadn't quite managed to match up all the information. Its second attempt was a lot more convincing. The whole process took just seconds.

Forrester had then needed nearly three-quarters of an hour to scribble out the report, and had nearly been late for work as a result.

Reed was poring over the data. 'Roz, what you've managed to do is impossible.'

'Yeah, well, six impossible things before breakfast and all that. Which reminds me, let's order, I haven't eaten yet.'

'So we're too late? They've already built superbombers?'