The camera cut away to a shot of Fostel laid out in splendid robes before an altar. The camera moved in closer to show his face and the red-stained bullet-hole in his chest.

'There will be a special service of remembrance at the cathedral at midday,' Zeckler continued. 'Meanwhile we demand that those involved with this foul crime be brought to justice immediately. They are Captain Benadik Lant of the City Watch, two as yet unidentified watchmen and the aliens known as the Doctor, Ian Chesterton and Susan Foreman. If, by the end of the service, those named have not been taken into custody, then I call on all Believers, and others who hold truth and justice in high regard, to march on City Hall and demand an explanation from the mayor himself.

'Go with the blessing of the Maker upon you.'

The screen blanked.

Draad was cursing under his breath: '...d.a.m.n the man!

Even after he's dead he still causes trouble.'

Pardek shrugged. 'Do you suppose Lant actually killed him? He didn't mention specific casualties.'

'It doesn't matter how Fostel died or who did it,' said Draad. 'Zeckler's going to tear the city apart with a rabble-rousing speech like that. The fool!'

'Listen, Mayor, I've got to follow this up now the accusation's been made. I must bring Lant and the others in if only for their own safety. If some of those fanatics get to them first, well, you can guess what might happen.'

'I know... but I'm not going to hand them over to Church justice just like that. Especially Lant. Despite everything he's a good man.'

'Yes, he is,' Pardek agreed. 'But maybe too honest for his own good? That is why we kept him off the list, after all. Will it make any difference in the end?'

Even as Draad slowly shook his head, Monitor interrupted sharply: 'I am now detecting major gravimetric changes on the moon.'

They turned back to the wall screens in time to see fountains of fire boil up through the clouds enshrouding the moon. They rose in seemingly graceful slow motion, sending showers of sparks out into s.p.a.ce. Draad blinked. Sparks? To appear as sparks on this scale the smallest point of light would have to be the size of a tower block. The fire fountains merged into a solid jagged line that cut across the moon's surface, curving about the rim. On another screen he saw the crooked tendril of fire creep inexorably on round the moon. Then, appearing over the moon's limb, came a second line of incandescent fountains.

The two rifts met and merged, encircling the moon in a ring of fire. The ring became a chasm which gaped wider and deeper by the minute.

Then came a blaze of light rising from the very heart of the chasm.

An almost perfect halo of flaring rock and dust was flung out into s.p.a.ce, expanding in apparent lazy slow-motion.

'The core of the moon has exploded,' Monitor announced.

Draad and Pardek stared in horrified fascination as, with ponderous majesty, the two segments of the moon began to drift apart.

'Internal pressure and gravitational stress has split the moon into two bodies of unequal size, the larger approximately twice the ma.s.s of the smaller,' Monitor continued unemotionally. 'In addition there are numerous secondary fragments of magnitude one kilometre and over. I am calculating the modified orbital dynamics of the new bodies now.'

Silently Draad crossed to his drinks cabinet and poured two gla.s.ses of a strong mixture he rarely touched. With his back to Pardek he took a pill from his pocket dispenser and swallowed it, then returned to the desk with the drinks.

'First approximation,' Monitor said. The larger body has been raised to a higher orbit by the force of the separation. It will not strike Sarath for at least sixty days. Secondary fragments will begin impacting within one hour. Significant atmospheric and seismic disturbances of progressively increasing intensity can be expected. The lesser body will strike Sarath in approximately right hours' time. The effects of the impact on the biosphere and planetary crust will be only 15 per cent less than that projected for the original body, since its angle of impact will be slightly greater. Possibility of survival for life on Sarath remains negligible.

'Today is Zero Day. I am awaiting further instructions.'

Pardek downed the remaining contents of his gla.s.s in one gulp, then looked at Draad. Like Monitor he was waiting for an answer.

Draad forced himself to take a more measured swallow of his drink. He felt curiously detached. Though no event had ever been so completely planned for in Arkhaven's history, now that it was upon him he could not believe it. All he knew for certain was that the next few hours would be both wonderful and terrible. One history would end and another begin... or everything would be lost.

It was almost by reflex that he cleared his throat and said: 'Monitor: initiate Operation Exodus immediately.'

Chapter Twenty-Eight.

Exodus The same message flashed over every public screen, house vidi and pocket phone in the city. The text scrolled up the screens in a continuous loop even as Monitor's measured tones provided a verbal accompaniment.

'ATTENTION ALL CITIZENS OF ARKHAVEN. This is an important announcement from the Mayor's Office. Today is Zero Day. Operation Exodus will begin immediately. Please cease all other activities and make your way to the launch site in an orderly manner, taking with you only your permitted item of baggage for personal effects. There is no need to hurry. The City is in no immediate danger and the Ship will not launch for a minimum of three hours. This is not an exercise.

'Message repeats: ATTENTION ALL CITIZENS...'

There was a metallic snap. Susan straightened up and examined the blade of her battered shovel, twisting a sliver of bent metal free.

'We'll wear these things out if we keep digging right up to the end,' she said.

'We can't stay here that long,' Barbara snapped. 'We must get back to the city.'

Susan gave her friend a curious look. 'I know, but we have to think of a way first.' She frowned thoughtfully at the piece of metal in her hand.

'All of you: down tools!' the guards began shouting.

'Leave them where they are! Back to base! Move it!'

The workers toiling along the embankments looked up in surprise, disconcerted by the sudden change in routine. There was a slow clatter of picks and shovels and a shuffle of feet as they formed up into their work teams. At another word of command they started back at a half-walk, half-trot.

'Do you think there's a storm coming?' Plax asked.

'They would tell us if there was,' said Semanov. 'There would only be a two-or three-minute warning. No time to get back to the cave so we shelter in the ditch. This is different.'

Two trucks pulling trailers raced past them towards the teams working further along the embankment.

'I think this is it,' Tressel said, panting with the effort of keeping up.

'What do you mean?' Barbara asked.

'The exodus... it must have begun!'

Those who heard him stumbled and broke step. The guards shouted at them to keep together.

'I thought there was still a month to go,' Susan said.

'How can we find out for certain?' Barbara asked. 'I must know for certain!'

Susan looked at her in surprise. There was a very strange look about Barbara's eyes. 'Are you feeling all right?'

But Barbara didn't seem to hear. She was looking about her with quick, darting movements of her head while her hands were clenching and unclenching nervously.

They reached the foot of the winding path that led to the cave complex and started climbing up it. Guards on the ledge under the cliffs above them shouted to them to hurry. Looking back across the plateau floor they saw rising clouds of dust as the trucks raced back with the first three work teams.

'Something's stirred them up,' said Plax. 'If it is the exodus, do we just let them lock us up and leave us?'

'Be quiet!' Barbara said, with such startling ferocity that Susan and Plax were shocked into momentary silence.

They were pa.s.sing the mouth of the cave they had been taken to when they arrived at the complex. Echoing faintly from within they heard an unemotional voice saying: '...and the Ship will not launch for a minimum of three hours. This is not an exercise. Message repeats...'

Barbara's eyes glazed. She pulled off her wrist.w.a.tch, turned it over and pressed her nail hard into a groove in the base plate.

Susan gaped at her in astonishment. 'What did you do?

What's the matter with you?'

Barbara blinked and shook her head, looking foolishly at the watch still clasped in her hands. 'I don't know... I had to do it. I've got to get to the Ship. Yes, I've got to get to the Ship!'

By now they had been herded through to the end of the equipment cave. The heavy door leading to the barracks stood open before them. Some workers, inured by routine, had stopped to remove their boots and coveralls and hang them up.

They were being harangued by impatient guards. The end of the cave began to choke with milling figures.

Heedless of Susan's cries to stop, Barbara began trying to claw her way back to the entrance of the cave, through the crowd of workers. With desperate strength she pushed a man out of her way. He tripped and pulled somebody else down with him as he fell. Voices were raised, blows exchanged and suddenly a scuffle began with Barbara in the middle. The guards waded in, swinging their guns menacingly.

Barbara dragged herself out of the struggling throng and stumbled awkwardly towards them, her eyes wild with blind determination. A guard shouted a warning but she took no notice. As she tried to push past him he reversed his gun and jabbed with the stock. It cracked against her forehead and she dropped to the ground.

Commandant Breen was in his office in the NC2 camp when the warning came through. After a shocked moment he recovered himself and remembered his duty. He sent a call out for the senior guards to see him at once, then took the packet of sealed orders from his safe. TO BE OPENED ONLY ON RECEIPT OF OPERATION EXODUS ALERT was stamped in large letters on the outside.

He tore the envelope open and unfolded the single sheet of paper within.

When the senior guards arrived he was still sitting at his desk, his normally florid features ashen.

'It's Zero Day,' he said in a dry voice. 'Withdraw the guards quietly, seal all the internal gates. Be ready to move out in ten minutes.' He silenced their sudden babble of questions with a sharp gesture. 'Just do it!' he snapped. 'The sooner we start the sooner we get to the Ship.'

Once they had left he got up and put on his coat. There was nothing else in the office that he valued. In fact he wanted no mementoes of the camp whatsoever. Memory would be a heavy enough burden to carry with him.

He took one more look at the paper lying on his desk. He didn't want to touch it again. It would be the only time he had ever failed to carry out orders. He supposed technically it was dereliction of duty, but this wasn't a war. He was no murderer.

And besides, who would ever know?

As he stepped to the door he heard shouting from outside.

'Are you positive it's her signal?' Keldo asked Thorken. 'We are still many days from the projected impact date. We reasoned the Arkavians would not be ready to launch until close to the end.'

'The signal was faint but unmistakable, My Prince,' the old scientist said. 'She must have survived the flood in the tunnels and is now obeying her instructions.'

'Could it have been transmitted by accident?'

'Not by the agent. Her conditioning makes it impossible for her to send the signal unless she is certain the evacuation of the city has begun. Perhaps something has happened to make them accelerate their plans.'

Keldo brooded for a moment, then said: 'We cannot risk ignoring the warning.' He opened the ship's speaker circuit.

'This is Keldo. The time has come, my warriors. Prepare for battle!'

In the hospital they were still trying to come to terms with Zeckler's incredible announcement when the alert came through. From the treatment room they could hear Monitor's message repeating over the public screen in the waiting area.

'I thought you still had thirty days left?' Ian said to Lant.

For a moment Lant appeared to have lost his customary composure. Then he put a call through on his phone and listened for a minute.

'There's been a ma.s.sive volcanic eruption on the moon,'

he reported. 'It's split in two. One part is going to hit us in about eight hours, but smaller fragments will start impacting from one hour onwards.'

Ian looked in dismay at the Doctor. 'Eight hours. Not time enough to make a new key for the TARDIS, I suppose?'

'No, Chesterton,' said the Doctor grimly, 'not nearly time enough.'

'Come to the Ship,' said Lant. 'I'm sure the mayor will agree to you joining us after the help you've given. At least you'll have the same chance as we will.'

'And me?' the android Susan said in a small voice.

As they hesitated the Doctor said firmly: 'My Susan is in this city somewhere. I will search to the last minute to find her. She may even still have her TARDIS key.'

Ian saw the look of determination in his face and didn't try to argue, though he was aware of how slim their chances were.

He had to stand by the old man. 'All right, but where do we start?'

'That health club... it's the only lead we have.'

Lant was looking troubled. 'I can give you a car, but I'm afraid you'll have to go alone. I've got to let my driver go and get to the Ship myself.'

'And I've got to help evacuate the remaining patients,'

Nyra said.

'But we may need your help,' Ian said. 'You know the city. Besides, don't you want to find out who made the android and why? Hasn't that got security implications?'

Even as Lant considered this, his phone rang. He listened for a minute, then said: 'Right, we'll be there as soon as we can.' He rang off and turned back to Ian and the Doctor with a very curious expression. 'That was Curton. He thinks he's found where your friend Barbara left the drainage system.

Now he says she might be with somebody who has the initial "S" in their name.'

'S!' the Doctor exclaimed.