The truth of the matter was, he didn't understand how the Machine worked, and never had. Professor Kettering was the kind of scientist who owes his position more to a polished convincing manner, a talent for political intrigue, and the ability to charm and flatter those in positions of power, than to any real scientific ability.

Conscious as he was of the hollowness of his scientific pretensions, Kettering had been flattered and delighted when Emil Keller had chosen him to oversee the first use of the Keller Machine in England. Eager for the reflected glory, Kettering had acted as Keller's sponsor, using all his considerable influence to secure the acceptance of the Keller Process by the Government, at least on an experimental basis. He had finally convinced them to set up a trial experiment, here at Stangmoor Prison.

Of course, Emil Keller had had explained how the Machine worked... But somehow the explanation was never really clear in Kettering's mind. He could remember only a low hypnotic voice, painting glowing pictures of the scientific distinctions to come, a knighthood, a peerage, perhaps even a n.o.bel prize. explained how the Machine worked... But somehow the explanation was never really clear in Kettering's mind. He could remember only a low hypnotic voice, painting glowing pictures of the scientific distinctions to come, a knighthood, a peerage, perhaps even a n.o.bel prize.

So far Kettering had succeeded in concealing his ignorance with a good deal of high-flown scientific gobbledegook. Now things had suddenly gone terrifyingly wrong. To make matters worse, this Doctor fellow was poking around asking awkward questions of a kind that Kettering was quite unable to answer. With steadily mounting unease, Professor Kettering went on going through the motions.

Suddenly the Keller Machine began throbbing with power... The electronic pulsing began...

Kettering looked at the Machine in astonishment. He hadn't switched it on, hadn't even touched the power switch.

Loosening his tie, Kettering began adjusting the controls, trying to shut off the Machine...

Shouts and yells were echoing along the corridors of the prison, tin plates and cups being rattled against the bars.

Chief Prison Officer Powers hurried onto the scene, and found his colleagues vainly trying to quell the noise.

'Starting up again, are they?' said Powers grimly. He added his powerful voice to those of the others. 'All right, now, quieten down there. Let's keep it down!'

But the prisoners took no notice. Something was stirring them up.

There was something familiar in the atmosphere, and suddenly Powers realised.

It was like Barnham's 'execution' all over again...

Kettering worked desperately at the controls, but it wasn't the slightest use. The Machine ignored him, as if it had a life of its own.

The weird electronic pulsing rose higher, higher...

Suddenly Kettering became aware that water was flowing under the door, and pouring down the walls, flooding across the floor...

The room was filling up with water, green billowing waves of it...

Kettering screamed. He had always been afraid of water, ever since he had nearly drowned in a boating accident when he was still a child. Even now he still couldn't swim, couldn't so much as get into a boat...

He screamed again as the cold waves rose over his head, choking him.

Kettering drowned.

As the Doctor and Jo hurried into the Process Chamber, Doctor Summers looked up from Kettering's body. 'He's dead.'

'Dead?' repeated the Governor. 'Do you know what happened?'

Summers shook his head. 'I'm not sure... it seems as if...

but it's incredible..

'Come on, man,' snapped the Doctor.

'Well, from the appearance of the body, the tinge of the skin and so on ' Summers took a deep breath. 'All the symptoms are consistent with death by drowning.'

The Governor gazed around the perfectly dry room.

'That's ridiculous, impossible.'

'Like the rats,' said the Doctor thoughtfully.

Summers looked worriedly at him. 'I think I'll go and check on Kettering's medical records.'

'Good idea,' agreed the Doctor. 'How long would you say he's been dead?'

'Matter of minutes. Five at the outside.'

Jo looked at the Doctor. 'That must be about when the riot started.'

'Exactly, Jo.'

The Governor said incredulously, 'Are you suggesting there's some connection?'

The Doctor pointed accusingly at the squat shape of the Machine. 'This thing has the power to affect men's minds and it's growing stronger.'

'Come now, Doctor,' said the Governor uneasily. 'It's only a machine.'

'Maybe and maybe not. Whatever it is, it's dangerous, and it's got to be destroyed now.'

'I've no authority to do that. Naturally, I'll report your recommendations to the Home Office, Doctor. They'll have to decide.'

The Doctor said grimly. 'I see. I wonder how many more deaths it will take to convince them?'

The Peace Conference had taken over one of London's most exclusive luxury hotels. For the period of the conference, the entire hotel would be occupied by the delegates, their aides and secretarial staff, and members of the security services of the countries involved. UNIT had overall responsibility for the security of the conference and the safety of the delegates.

And UNIT had failed, thought the Brigadier, as he stared down at the crumpled body of General Cheng Teik.

No marks on the body, an expression of unbearable terror on the face, and that was all.

Someone, or something, had broken through an impenetrable wall of security and killed the General, endangering not only the success of the Conference, but the peace of the entire world.

The accusing voice of Chin Lee broke in on his thoughts. 'First theft, then murder, Brigadier. What are you going to do about it?'

The Brigadier looked thoughtfully down at her. 'Who else knows about this?'

'No one. I called you at once.'

Mike Yates murmured, 'Should I call the police, sir?'

'Just a courtesy call. Tell them we'll handle this ourselves. I want a full check on movements in and out of this suite, Captain Yates, before and after the General's death. And no Press! D Notices!'

'Right, sir.'

As Yates moved away, the Brigadier called, 'And then go and get the Doctor back from Stangmoor. I want him here!' He turned to Chin Lee, who was standing stiffly before him, the black eyes glaring accusingly.

'Now, Captain,' said the Brigadier, 'I'd like to know exactly what happened in detail, please.'

'My appointment with the General was at twelve p.m.

There were some details to discuss about the Conference.'

'And you were punctual?'

'I am always punctual, Brigadier. I showed my pa.s.s to your UNIT sentry and entered the General's suite as the clock was striking twelve.'

'Go on.'

'There is nothing more to say. I saw the General's body, and telephoned you.'

'Immediately?'

'Of course.'

The Brigadier glanced at his watch. 'Excuse me a moment, Captain.' He turned to Corporal Bell, who was hovering nearby and said quietly, 'I want you to check on the precise time of Captain Chin Lee's phone call.'

The Doctor and the Governor had been arguing for some time, but the Governor refused to budge. 'I'm sorry, Doctor, that's my final word. I'll suspend any further use of the Keller Process and I'll put this room out of bounds.

But that's all I can do without higher authority.'

Reluctantly, the Doctor accepted defeat. 'All right. Then I'd better do what I can to make this Machine safe.' The Doctor tossed his cloak over a chair.

'I'll help, Doctor,' volunteered Jo.

'I'll do it on my own.'

'Is that wise?' asked the Governor.

'Perhaps not, but I prefer to work that way. How long has this Machine been installed?'

'Nearly a year. Emil Keller himself came over to supervise the installation.'

For no particular reason, the Doctor asked, 'Did he have anyone with him? An a.s.sistant?'

'Actually he did. A rather attractive Chinese girl...'

The atmosphere in the Chinese delegate's suite was heavy with tension as Corporal Bell put down the telephone, scribbled a note on a pad and handed it to the Brigadier.

He studied it, then looked up. 'Captain Chin Lee, you say you phoned me at twelve immediately you discovered the body?'

'Of course.'

The Brigadier shook his head. 'No, Captain, you telephoned me at twelve-fourteen exactly.'

'You must be mistaken.'

'You called on a security line, Captain. All security calls are logged.'

Chin Lee was silent.

'Well?' demanded the Brigadier. 'Why did you wait for almost a quarter of an hour before reporting the crime?'

Despite the Doctor's orders, Jo insisted on hanging around while he checked over the Keller Machine. 'What are you doing, Doctor?'

'Hunting,' said the Doctor briefly. 'And will you please let me get on with it?'

'I'm only trying to help.'

'Yes, of course you are. Look, why don't you go along and see if Doctor Summers has got any more information about Kettering's death?'

'Right. I'll bring it straight back here.'

'No!' said the Doctor hurriedly. 'Take it to the Governor's office. I'll meet you there later.'

'Okay!' Reluctantly Jo headed for the door.

'Well, off you go then.'

Jo turned away, but she couldn't resist turning in the doorway, for a final look at what the Doctor was doing.

Without turning round the Doctor shouted, 'Boo!'

Jo jumped, and scurried from the room.

She found Doctor Summers in the medical wing, and pa.s.sed on the Doctor's request.

Summers pointed to a pile of papers on the table. 'I've just got the post mortem report.'

'What's the verdict?'

'Kettering's lungs were full of water. He drowned in the middle of a perfectly dry room.'