Jo tried to follow but the Master barred her way. 'No, Miss Grant, you will remain here, as a guarantee of the Doctor's good behaviour.'

The Master stepped back, and the door was closed.

The Brigadier was giving a final briefing to Major Cosgrove and the two young officers who would be commanding the attack force. 'We shall, as you realise, be very considerably outnumbered. However, not all our opponents will be armed, and none of them will be trained soldiers.'

Cosgrove said brightly, 'And of course we will have surprise on our side.'

The Brigadier, who had planned to conclude his address with that point gave Cosgrove yet another quelling look.

'Exactly! Now, any questions?'

'No questions, sir,' said Cosgrove, before anyone else could speak.

The two young officers saluted and marched out.

'It's an excellent plan if I may say so, sir,' said Major Cosgrove. 'I should think there's a very good chance of success.'

'Thank you,' said the Brigadier drily. 'I'm very relieved.'

Cosgrove moved off to check the movement orders.

There was a tap on the door and Benton appeared, a little pale but otherwise back to normal, apart from a patch of plaster on the crown of his head.

The Brigadier looked up. 'What the devil are you doing here, Benton? You're supposed to be in hospital.'

'I discharged myself, sir. I'm all right now, just a bit of a sore head.'

'Well, what do you want?'

'I'd like to come on the a.s.sault, sir.'

'Benton, for all we know you may be suffering from severe concussion ' began the Brigadier.

'It's only a scratch, sir,' said Benton desperately. 'You always said I'd got a thick head. I'd just like a chance to get at the blokes who did it.'

The Brigadier nodded, accepting the inevitable. 'All right, Sergeant Benton. If you're sure you feel fit you can take charge of the underground a.s.sault party. Major Cosgrove will put you in the picture.'

Benton saluted. 'Thank you, sir.' He hesitated. 'I suppose there's no news of Captain Yates?'

'I'm sorry, Benton, there's nothing. Nothing at all.'

In the hangar office, Captain Yates was still sawing frantically at the ropes that tied his wrists. The strut had proved too smooth, but Mike had managed to get out of the chair, and he was trying his luck with the edge of an old metal table.

Suddenly, to his delight, the frayed strands of rope began to part just as he heard footsteps coming towards the door...

13.

The Attack By the time the guard came back into the hut to check up on his prisoner, Mike Yates was slumped back in the chair.

Suspiciously the guard approached to check the bonds.

As soon as he was in reach, Mike grabbed him and threw him neatly over his head in a cla.s.sic judo throw.

Pausing only to make sure that the man had been knocked out by the fall, Mike crept cautiously from the hut.

It had taken the Doctor quite some time to choose the equipment he needed from the Prison Workshop, and an even longer time to a.s.semble it to his satisfaction.

He had transferred the lot to a warder's office close to the Process Chamber, where he was engaged in checking it over once again. He was wearing a white coat, heavy gloves and a protective helmet with a transparent visor.

The results of the Doctor's efforts consisted of a huge electrical coil, in the form of a loop on the end of a very long length of wire, rather like a giant la.s.so.

The wire was connected to a square black box studded with controls, a rather special form of junction box, and this in turn was connected by yet more flex to the prison power supply.

The Master stood looking on, fuming with impatience.

'Doctor, you must hurry. If that thing starts moving again...'

'I am well aware of the importance of the situation,' said the Doctor calmly. He picked up the coil in one hand and the junction box in the other and carried them out into the main area of the prison, moving along the corridor and placing them as near to the Process Chamber as possible.

The Master watched in some puzzlement. 'May I ask what you intend to do, Doctor?'

'I'm going to try to throw this coil around that Machine in there if I can get close enough without being killed.'

'I see and what can I do to help?'

It was very clear from the Master's tone that any such help would be given from a safe distance.

The Doctor pointed to the junction box. There was a control panel, studded with lights and dials. 'I want you to operate these controls here. Switch them on to full power when I shout.'

The Master studied the box. 'Very ingenious. What does it do?'

'If all goes well, the box will set up an electric current in the coil a current alternating on much the same frequency as the human brain.'

'And what will that do to the mind parasite?'

'I'm not sure but I hope hope it will confuse the creature enough to inhibit its powers of movement.' it will confuse the creature enough to inhibit its powers of movement.'

'I hope you're right, Doctor.'

'So do I,' said the Doctor grimly.

He picked up the coil and set off.

The Master took his place at the controls. 'Good luck, Doctor.'

The Doctor moved along the corridor, trailing flex behind him. He reached the door of the Process Chamber, opened it cautiously, and moved inside.

Sure enough, the Machine was back in place.

Perhaps the creature inside regarded the place as a kind of home, thought the Doctor. Perhaps it felt safe there.

The Doctor crept cautiously forward. He got quite close before the Machine reacted to his presence with its menacing, throbbing sound.

The sound built up with terrifying speed and suddenly the Doctor found that he was forcing himself forwards, struggling every inch of the way with the terrifying powers of the creature in the Machine.

Inside the transparent column the spongy ma.s.s was pulsating violently. It threw hallucinations at him in rapid succession; flames, Daleks, Cybermen and all the others.

The electronic pulsing grew louder and louder. Somehow the Doctor managed to resist. He staggered closer and ever closer until at last, with a desperate heave, he was able to throw the coil over the Machine.

The Doctor backed away.

'Now!' he shouted over his shoulder.

Out in the corridor, the Master was working frantically on the junction box controls, trying to stabilise the power levels before the box overloaded and blew up. Warning lights flashed on the control panel, and the box began to smoke, growing hot to the touch. He managed it at last, and the lights flashed less wildly, and the smoke and heat died down.

In the Process Chamber the throbbing and pulsing of the Machine died down too.

The Doctor turned and walked wearily away.

He found the Master waiting in the corridor, Mailer beside him.

'My congratulations, Doctor,' said the Master generously.

'It won't hold it for long, you know,' warned the Doctor.

'That thing's intelligent intelligent. Soon it will work out what's happened and find a way to deal with the coil.'

'Then you'll have to think of something better, won't you? Mailer, take the Doctor back to his cell.'

The Master swept away.

Mailer jabbed the Doctor with his automatic. 'All right, come on, you.'

Jo looked up as Mailer shoved the Doctor back into the cell. The Doctor took a few steps and collapsed onto the bed.

Jo sat beside him, concerned. 'Are you all right, Doctor?'

'I'm fine, Jo,' said the Doctor wearily. 'Fine.'

'Did you fix the Machine?'

'Temporarily.'

'You look tired.'

'I am! Physically and mentally.' Wearily the Doctor began stripping off the protective clothing.

Jo had never seen the Doctor in such low spirits. 'Hey, how about some food?' she said brightly. 'Do you think they'll give us any?'

'I doubt it not after what we did with the last lot!'

'We've had nothing all day I'm starving,' protested Jo.

The Doctor smiled. 'Well, I suppose we shouldn't have hit them over the head with our breakfast!'

Jo jumped up. 'Breakfast. Wait a minute!'

She scrabbled about under the bed and emerged with two dusty pieces of cold toast. 'I knew they wouldn't bother to clean up.' She held one out to the Doctor, who recoiled.

'No thanks, Jo, you have it. I can go for quite a time without food, you know.'

'No, no, we'll share it,' insisted Jo. 'And there's still some water in the jug there.'

Jo poured out two gla.s.ses of water, gave a piece of toast to the Doctor.

She raised her gla.s.s. 'Cheers!'

'Cheers!' said the Doctor solemnly.

They settled down to their feast.

'Did I ever tell you about the time I was locked up in the Tower of London, Jo?' said the Doctor suddenly.

'No, I don't think so.'

'I shared a cell with a very strange chap called Walter Raleigh. He'd managed to get on the wrong side of Queen Elizabeth, you see the first Queen Elizabeth. Anyway, he kept going on about some new vegetable he'd discovered, called the potato. Well, one day old Walter sat down and pointed a finger at me and said, "Doctor..."'

A large plain van drew up to the gates of Stangmoor Prison and its overalled and cloth-capped driver got out, and nodded cheerfully to the tough-looking guard.

'Morning, mate. Provisions!'

He was a tall man with a clipped, military moustache.