'Now look here, Mr Vincent or whatever your name is, let's get one thing clear. I'm in charge here. I'm responsible to UNIT for Miss Grant's safety, and I would appreciate it if you would put that gun away now.'

Vincent said simply, 'No,' adding after a moment, 'And my name is Al Tayid Al Tayid.' His voice was cold and menacing.

Suddenly Jo had had enough. 'Stop it!' she said. 'Both of you stop it! There's nothing we can do but carry on. I - I don't know what's happening to me, but I'm quite human at the moment. I want to destroy the Xarax as much as you do.' - sweet sweet honey honey sweet sweet honey honey sweet to be honey to be good honey sweet to be honey to be good honey - 'More than you do.' - 'More than you do.'

Vincent slowly lowered his gun, and Mike put his away. 'But we will keep an eye on you, eh?' he said.

Jo looked at her hands. They were swollen, she realized; the knuckles were almost invisible beneath the stretched skin. 'If I start acting like one of them,' she said. 'Just kill me.' - Benari, blood Benari, blood pumping from his head pumping from his head - 'Just do it. And don't try to stop him, Mike, or they'll get both of you.' - 'Just do it. And don't try to stop him, Mike, or they'll get both of you.'

Mike put a hand on her shoulder. 'It won't come to that, Jo, I'm sure.'

Vincent was silent.

Jo became aware that she was trembling violently, and that she badly needed to pee. She got out of the jeep, grinned at Mike. 'I need to disappear behind a rock.'

Mike grinned back, but Vincent was over the back door of the jeep, gun at the ready. 'I will cover you,' he said.

There was a deep gully by the side of the road which she decided in the circ.u.mstances would just have to be private enough. She kept expecting Vincent to appear on the side of the road above her, but he didn't. When she was finished, she walked along to the end of the gully, where the slope back up to the road looked as if it would be easier to climb.

She was just about to scramble up the slope when a hand grabbed her arm. She whirled round, found herself staring into the barrel of a revolver.

'Miss Grant!' said Sadeq Zalloua. 'I'm glad you're here. I don't think I could have travelled much further on my own.' He jabbed the revolver against her throat. 'Walk slowly, please.'

Twenty-Five.

F'You were being escorted by terrorists terrorists?' The Moroccan officer seemed incredulous. He gazed at the Brigadier in the dim light seeping in from the open turret of the tank. 'You know who Al Tayid Al Tayid is, don't you?' is, don't you?'

'Yes,' said the Brigadier wearily, shifting his injured leg in a vain attempt to get comfortable in the cramped s.p.a.ce. 'I know who he is.'

He decided not to mention the fact that his erstwhile escort detail had just a.s.sa.s.sinated their Prime Minister. Rashid was technically on secondment to the UN; but he was still a Moroccan, and the Moroccans were friends of Khalil Benari's. If Rashid knew what had happened he was just as likely to follow his own agenda, and it might not include taking the Brigadier and the Doctor to Rabat. 'Look, we need to get out of here. The place is crawling with aliens and Kebirian Army, and it may not be possible to tell the difference between them.'

'Well - if you say so,' said Rashid. 'But I think it may be more useful to stay put. We can send for reinforcements. The aliens are, as you say, mostly out of action at the moment.'

'I'm afraid not,' said the Doctor from the driver's seat of the tank.

He gestured at the blurry screen of the tank's battle radar. The Brigadier saw several fast-moving blips.

'What are they, Doctor?' he asked.

'I don't know, Brigadier, but judging by the rate they're going I'd say they're potentially dangerous.' The Doctor started the tank's engine. Lights flashed on the control board, and the whole body of the vehicle shuddered as it began to grind forward over the rough ground.

Rashid reached for the radio mike. 'Rashid to all units. Rashid to all units. We're moving out, repeat, moving out.' He flicked off the mike.

'I hope you realize, Doctor, that we will be more vulnerable to air attack when we are moving than if we stayed put and used our anti-aircraft defences.'

'These aren't exactly aircraft,' said the Doctor. 'Machine-guns should be enough to bring them down, if they're aimed properly.'

'I hope you're right, Doctor,' said Rashid.

'So do I,' said the Brigadier.

'Of course I'm right,' said the Doctor irritably. 'You saw what happened to the first two yourself. Really, Brigadier, I can't understand why you don't have more faith in me.'

He turned the wheel sharply, and the tank lurched onto the road.

Sergeant Benton crept across the gravel path, peered cautiously over the sill of the broken window.

He saw an empty office. A typewriter turned over on the floor. A broken vase.

He looked over his shoulder, beckoned to his men, then turned back and reached inside the broken pane to the handle. It turned; he carefully pulled the window open, then clambered in over the sill.

There was blood on the floor of the office, staining the carpet. He picked his way around it, past the map of the world on the wall, to the heavy door.

It wasn't locked. He checked behind him to make sure that his men were on their way in, then opened the door.

On the other side stood the Doctor, facing him. He smiled. 'Ah, there you are, old chap. We could do with a hand here, you know.'

Benton raised his gun, aimed it at the copy's head. He thought: this isn't the Doctor. I know it isn't. It's an alien and it's killed my mates.

It's killed John Sh.o.r.egood and Barry Ryman and it'll kill the rest of us if we let it.

'Now don't be foolish, sergeant,' said the copy, still smiling. 'You know that we need your help.'

It was then that Benton noticed the blood on the alien's hands.

Fresh blood.

He tightened his finger on the trigger.

- I've got to fire I've got to kill it now before it kills me I've got to fire I've got to kill it now before it kills me - - But he couldn't do it.

There was a movement behind him, a sudden intake of breath. The copy flew forward, impossibly fast, pushed Benton over. He felt its hands close around his throat.

He saw one of his men stepping over them, heard a shot.

The copy jolted back, rolled across the carpet. Benton saw a hole in its head, leaking blood, but it didn't stop moving. Slowly it stood up again, casting around as if blind.

'Fire at will!' he yelled as he scrambled to his feet.

Guns clattered, but n.o.body actually opened fire. 'What's the -'

Benton started to say.

Then he saw them, marching around the corner of the hallway.

John Sh.o.r.egood. Barry Ryman. The others. Their faces were blank, and their feet made chitinous clicks on the vinyl flooring as they advanced towards him.

Jo's head was full of ifs.

If she hadn't needed to go so badly. If she hadn't been so modest and had just gone by the side of the road whilst the men turned their backs. If there hadn't been that horrible argument that she'd needed to get away from.

'Sorry,' she said, as she returned to the jeep. 'I've messed it up.'

Vincent and Mike turned to stare at her, saw Zalloua, drew their guns.

'Throw the weapons down,' said Zalloua. 'Or Miss Grant dies.'

'Now just a minute -' began Mike.

Vincent opened fire.

Bullets whizzed past Jo's ear; she heard Zalloua cry out, then the crack of the revolver.

'Get down, Jo!' shouted Mike.

But it was too late. Zalloua had hold of her again, an arm around her neck, the revolver against her skull.

Mike dropped his gun to the ground, put his hands up. She couldn't see Vincent.

'Good,' said Zalloua. 'Now get out of the jeep.'

Mike got out.

'Kick the gun across to me.'

Mike obeyed. Jo caught his eye, twisted her face into an expression of regret and sympathy. Mike managed the tiniest of shrugs.

Zalloua put his foot on the gun, reached down with his free arm. Jo saw blood running from it: thick, red blood. But he managed to pick up the gun, put it in the pocket of his tattered lab coat. Then he marched her towards the jeep, motioning Mike out of their path.

Then she saw Vincent.

He was lying in the back seat of the jeep. His mouth was open, with a thin trickle of blood running from it. There was a hole in his chest, bigger and messier than Jo would have thought possible from a single bullet. He was still breathing, and his open eyes stared at Jo.

'You!' shouted Zalloua, gesturing at Mike. 'Get him out of the jeep!'

Mike stepped forward, opened the rear door of the jeep, then reached in and took Vincent's legs.

'Touch the gun and I kill her!'

'I wasn't planning to touch it,' said Mike disgustedly. He pulled, and Vincent's body slid out of the car and on to the dry road, bashing Vincent's head brutally on the ground. He gave a little grunt of pain and fresh blood flowed from his mouth.

'You're killing him!' said Jo, struggling against Zalloua's grip.

'He is not a good man,' said Zalloua. 'And anyway, it is in the cause of peace. Get in the jeep.'

Jo got in, acutely conscious of the gun still against her head. She wondered if he would really fire it if she tried to escape.

But even as she thought about it, it was too late: Zalloua was in the jeep beside her.

'Start up the engine,' he said, then louder, for Mike's benefit. 'Try anything and she will be the first to die.' But Mike was out of sight, presumably trying to help Vincent.

Jo got the engine started; Zalloua prodded her with the revolver.

'Drive.'

Jo obeyed, driving as slowly as she dared. 'Where are we going?'

she asked after a while.

Zalloua stared at her through his round spectacles. 'Kebir City, of course,' he said.

'But we were going there anyway! Why did you have to - '

'And no doubt your orders were to destroy the Xarax?'

Jo stared at him. 'The Doctor said - '