Lieutenant Anthony Hemmings of the Freikorps stared incredulously at the two miserable figures standing rigidly to attention before his desk.

"To come straight back here," said Brady.

"And put ourselves under arrest," mumbled Harris.

"On what authority?"

When they didn't reply he rose to his feet, towering menacingly over them.

The contrast could scarcely have been more marked. Privates Harris and Brady wore the coa.r.s.ely made ill-fitting uniforms of rankers in the BFK, called, though not to their faces, the Black and Tans. They were stocky, pasty faced and pimply.

Lieutenant Hemmings himself was tall and dark and undeniably handsome.

His black uniform, modelled on that of the SS, had been elegantly tailored by a concentration camp inmate formerly of Savile Row. Its immaculate blackness was set off with silver deaths-head badges on collar and cuffs.

His jackboots gleamed evilly. "You were trying to extort money, of course,"

he drawled.

"No, sir," protested Brady.

Hemmings ignored him. "But you've committed a far worse crime than just extortion - by allowing yourselves, and therefore the whole Freikorps, to be made fools of! Did this man identify himself? Did he show any papers?"

Brady shook his head. "If you'd heard him, sir, he was someone all right. . .

"He was bluffing!" shouted Hemmings. "And who do you think would have the nerve for a bluff like that? A member of the resistance. Almost certainly a very senior member. Exactly the sort of man we're stationed on the Festival site to catch and you let him get away!"

The two privates stood there in terrified silence. Hemmings studied them, savouring the moment. "Now, what am I to do with you? I should really have you shot, but you're hardly worth the cost of the bullets. Hanging by piano wire's cheaper, but it's rather slow. . . " He paused, prolonging the agony. "Go back to barracks and report to the quartermaster sergeant.

You're on permanent fatigues in the toilet block for the rest of the week."

The two privates crashed to attention, saluted and doubled thankfully out of the office.

Hemmings smiled coldly as he watched them go. They'd been extorting money of course, they all did it. No one really minded. It was one of the perks of service in the ranks of the Freikorps. A little extortion, the occasional rape, the fun of arresting and beating up anyone whose face or clothes or colour you didn't like. It did no real harm, just ensured that the populace hated the Freikorps even more than the occupying power. By contrast, the Regular Army troops, the Wehrmacht, were almost popular.

Hemmings reached for his cap and gloves. It was time, he decided, to take a look round the Festival site. He hadn't much liked being a.s.signed to Festival duty. He regarded the whole Festival as a waste of time, a sick joke on the part of the Occupying Power. These days the British had precious little to celebrate. But to capture a senior resistance man would be a considerable coup. Lost in dreams of promotion and glory he strode from the office.

It was very quiet down by the river. Mist rose from the surface of the water, drifted between the piles of bricks and stacks of timber.

Suddenly the Doctor stopped. "Wait!"

"What's up, Professor?"

"Sssh! Just listen!"

After a moment Ace heard footsteps coming towards them, the sound of harsh, panting breathing. A man appeared from out of the mist dodging between the timber stacks and the concrete blocks. He wore a dark overcoat and a homburg hat, and he was small, dark and pudgy, with rimless gla.s.ses.

Could be a site foreman, thought Ace, but why's he running? Then she saw other figures at the man's heels, hunting him like wolves.

The Doctor was already hurrying towards the little man. At the sight of him the running man's face twisted in fear. It was clear he thought this was another of his enemies, cutting off his escape. He turned and ran in the only direction open to him - towards the river.

Just as the little man reached the edge of the embankment a tall white-haired figure sprang from behind a timber stack. His arm rose and fell. The little man stiffened and plunged over the edge of the embankment. The tall figure dodged back between the timber stacks and disappeared.

By the time the Doctor and Ace arrived, the little man was half in and half out of the water, twitching feebly like a stranded fish. The river was swirling around the lower part of his body, tugging at the skirts of the long overcoat.

"Quick, before the current gets him," shouted the Doctor. "Hold my ankles."

The Doctor threw himself forwards, stretching out, head first down the slippery wet concrete slope. Ace grabbed his ankles, noticing, not for the first time, that the Doctor had terrible taste in socks. The Doctor reached downwards, straining to grasp the little man's outstretched hand. Their hands touched, then the Doctor seemed to fumble. The little man slid suddenly into the river, and was immediately carried away by the fast-moving tide.

Ace hauled the Doctor back up the slope and he scrambled to his feet.

"I thought you'd got him..."

"So did I - I thought he was trying to grip my hand, but he was giving me this." The Doctor held out his hand revealing a small black leather folder.

He flipped it open. One side held some kind of pa.s.s, the other an ornate badge embossed with a golden swastika. "It seemed to be important to him. Somehow I got hold of this and lost hold of him."

Ace could see the body, turning over and over in the rushing river like a piece of driftwood. Soon it would be out of sight. "Shouldn't we go in after him?" she said unenthusiastically.

"No point. He died as he handed me that folder. I saw the life go out of his eyes -it's quite unmistakable."

They heard a distant shout. "You there! Halt! Halt or we fire!" Uniformed figures appeared on the far side of the site, running towards them.

The Doctor thrust the folder into his pocket. "Run!" They ran, dodging between the brick stacks and the piles of timber. They came at last to the gap in the fence and they both nipped through it.

"What do we do now, Professor?" The Doctor glanced over his shoulder.

"The trouble is, those people are between us and the TARDIS. We'll have to wait till they move on, then try to work our way behind them. Meanwhile, I suggest we join the happy throng for a bit."

Ace looked around. There were a few more people strolling round the Festival site by now. Still women and children and old people, she noticed.

"You couldn't call this lot a throng, exactly, could you? And most of them don't seem all that happy either."

"Neither would you be, after ten years under the n.a.z.is. Come on, let's take a look at the Dome of Discovery."

Ace found the Dome of Discovery almost as boring as the earlier exhibition.

It was filled with maps, charts and models, most of them devoted to a newly designed s.p.a.ce rocket. Apparently the n.a.z.is planned to mark this Festival year by landing a man on the moon.

"This is terrible," muttered the Doctor.

"I thought you liked this kind of stuff!"

"Don't you see what's happening? The n.a.z.is were doing pioneering work in rocketry by the end of the war - using them to deliver ma.s.sive warheads on London. The Allies had nothing nearly so advanced. If their armies hadn't overrun the missile sites, Hitler might still have won."

"Well, he did win, didn't he, here?"

"They were working on atomic energy too. Think of it, Ace! A ma.s.sive atomic research programme, driven by the ambitions of a war-mad megalomaniac dictator with an unlimited supply of slave labour and the resources of half the world at his command! It's madness. It's got to be stopped."

The Doctor's voice had risen, and a bespectacled little man nearby looked round in alarm. He scuttled away, looking, thought Ace, exactly like a startled mouse.

She turned back to the Doctor. "Stopped, how?"

The Doctor looked round the pavilion. "What we're seeing here are the effects of interference. I've got to work my way back to the causes, find out who interfered, and when, and why..."

"And then put things back the way they were?"

"If I can. Interference with an established timestream is always incredibly dangerous - and interfering with someone else's interference could be catastrophic. We'd better have another go at getting back to the TARDIS.

With any luck that patrol will have moved on by now."

As they moved towards the exit Ace said suddenly, "Hang on a minute, aren't we forgetting something?"

"What?"

"Well, we saw a murder just now."

"So?"

"Ought we to do something about it?"

"Like what? Play Sherlock Holmes? Go back to the scene of the crime and look for clues?"

"Report it to the authorities at least."

"And answer all the usual boring questions? Who are you, where do you come from, why haven't you got any identification papers and why are you wearing those funny clothes?"

Ace nodded. "It still doesn't seem right, ignoring someone's death. I wonder who he was, why he was killed."

"If that folder's anything to go on, he was a n.a.z.i official. Presumably he was killed by some kind of resistance movement. Or perhaps even by other n.a.z.is, political rivals. Human life means very little under this kind of regime."

"Human life doesn't seem to mean much to you either, Professor."

He gave her an impatient look. "The crime I'm concerned with now involves millions, billions of lives. I've no time to worry about one squalid little murder."

"Aren't you even curious?"

"No, not really. Are you?"

"I suppose I am. We saw him die - and we don't even know who he was..."

They had reached the entrance by now, and as they emerged into the watery sunlight an excited voice shouted, "That's them! They're the ones!"

Booted footsteps pounded towards them.

A four-man squad at his heels, Lieutenant Hemmings was patrolling the Festival site. Everything seemed quiet enough but then, with a Freikorps patrol around, it would be. He needed more and better informers, he decided, it was the only way. He'd reached the Dome of Discovery by now and, as if in answer to his thoughts, a furtive figure hurried up to him.

"Lieutenant Hemmings - it is Lieutenant Hemmings, isn't it?"

Motioning the patrol to a halt, Hemmings looked down at the mousy little figure. "Yes?"

"Don't you remember me, Lieutenant? Name of Arnold. I helped you with that black market case last month."

Pleased with the coincidence, Hemmings said, "Do you know, I was just thinking about you!"

Arnold looked alarmed. "Me, Sir?"

"Well, you, or someone like you. You've turned in quite a few of your fellow citizens in your time."

"I try to do my duty by the Reich," said Arnold primly.

"And turn a profit in the process. You've pocketed some nice little rewards, haven't you? How would you like to earn another one? There's a man I'm looking for." He pa.s.sed on the description of the Doctor he had been given by Harris and Brady. "Apparently there's a girl with him. . . "

Arnold was trembling with excitement. "I've just seen them, Lieutenant!"

"When? Where?"

"They were in the Dome of Discovery, talking treason! I was coming to look for you."

Hemmings turned to the patrol leader. "Cover all the entrances and we'll move in."

Before the patrol could move, Arnold shouted, "That's them! They're the ones!" He pointed to two figures at the entrance to the Dome.

Hemmings ran for the entrance, the patrol at his heels. In a matter of seconds the man and the girl were surrounded.

Arnold pointed to them with a trembling finger. "That's them!" he repeated.

"They were talking against the Glorious Reich, against the Fuehrer himself.

The man said he was a madman and had to be stopped."

Hemmings looked curiously at the man and the girl. There was something strange about them, he realized. Not just the oddity of their clothes, there was something more. Suddenly he realized what it was. They weren't afraid.

"Is this true?" he asked.

"Absolute rubbish!" said the man. "What I actually said was that anyone who opposed the Glorious Reich was a madman."

"You attacked two of my men, earlier, by the coffee stall impersonating a Party Official in the process."

"I impersonated no one. Ask them. They were committing a crime and I simply did my duty as a citizen."

Hemmings looked thoughtfully at him and then shook his head. "No, it won't do you know. It's just not convincing."

"It's our word against theirs," said the girl. "And why believe this man rather than us?"

"Well, he's one of my regular informants, you see. Quite a valuable little Judas, aren't you, Mr. Arnold?"