'Let them know what they're carrying.'

In the communications room of Station Alpha, Ferris, the station manager, a short, stocky, confident type, was congratulating his staff, and himself, on a model work-shift.

'Solar yachts and s.p.a.ce freighters, s.p.a.celiners and shuttle ferries,' he said eloquently. 'They arrived on time, they departed on schedule, and we handled them all. Well done!'

Dobbs, Ferris's number two, who was tall and thin and nervous, crossed his fingers behind his back. He felt that this kind of talk was tempting fate.

Dobbs was right.

Ten seconds later, a ma.s.sive alien ship appeared on the main vision screen. It was shaped like a ma.s.sive wheel, like two wheels, connected by a dome.

'What the h.e.l.l is that?' demanded Ferris. 'It's not a scheduled arrival!'

A voice blared from their com-unit speakers. 'Station Alpha! This is the Sontaran War Wheel. We are sending a boarding party. Do not resist. To convince you of our seriousness, we shall now fire one warning shot.'

Ferris ran to the com-unit. 'Must let people know what's happening.'

There was a shattering crash, and the whole station shuddered.

In the bar the Doctor, Roz and Chris were still making plans.

Roz lowered her voice. 'Can you catch up with Tiger Moth Tiger Moth, Doctor in the TARDIS?'

'Well, it's a tricky thing materializing on a ship in flight, but I've done it before usually when I didn't mean to.'

Their plans were interrupted by the blare of an alarm, followed by a panicky voice over the intercom. 'Everyone, please remain calm. It appears that this station is under attack by an alien military vessel...'

There was a crash of laser-cannon that shook the whole station and the voice cut off.

'Come on,' said the Doctor, heading for the door. Roz and Chris hurried after him.

'Where to?' asked Chris.

'The TARDIS. I checked her in at the storage depot.

Whatever's happening here, I want to be somewhere else.'

As they ran along the corridors towards the storage section they heard the clang of a docking craft somewhere ahead.

They turned a corner and ran into squat dome-headed figures in s.p.a.ce armour who covered them with blasters.

'Halt!'

They halted.

One of the figures stepped forward. 'I am Lieutenant Vorn, in command of this Sontaran a.s.sault Group. This station is in our hands. All personnel will a.s.semble in the main refectory hall. Obey and you will not be harmed. Resist and you will die.'

'Blast!' said the Doctor.

They were taken to the refectory, a big brightly lit hall filled with plasti-steel chairs and tables, with a long counter along one end. There were Sontaran sentries on the door. As they arrived, other occupants of the station, both pa.s.sengers and officials, were being rounded up and herded into the hall. A line of Sontaran troopers, blasters drawn and levelled, stood along the wall. They looked, thought the Doctor ominously, like a firing squad.

At the other end of the hall two Sontaran troopers were setting up a piece of apparatus. It consisted of two parabolic reflectors connected to a small console. A Sontaran officer stood by the console. Under the blasters of the a.s.sembled Sontaran a.s.sault force, the line of prisoners was made to pa.s.s, one by one, between the reflectors.

'What's going on, Doctor?' whispered Roz. 'What shall we do?'

'Just walk through like the others. Whatever happens, don't fuss. Don't draw attention to yourself. And don't call me Doctor!'

The Doctor was the first of their group to walk between the twin reflectors. The process produced a powerful tingling sensation throughout the body.

The Doctor was waved on, and stood waiting for the others.

When Chris went through the apparatus gave a high-pitched buzz. He was stopped, roughly searched, and his vibroknife, cosh and blaster taken away. He was waved on.

Much the same thing happened with Roz.

The three of them stood aside and watched the rest of their fellow captives file through.

Those who were armed had their weapons confiscated without comment.

During the entire procedure, no questions were asked, or answered. Those who protested were ignored. Those who made nuisances of themselves were clubbed into silence.

A burly mining engineer who tried to get tough was killed.

Things ran much more smoothly after that.

Roz was inclined to be indignant at what she saw as very sloppy security work.

'What a way to run a round-up,' she said. 'Even Chris could do better. They didn't ask us who we were or where we were going. They didn't even want to know why we were armed. What's going on?'

'That device is some kind of cellular scanner,' said the Doctor. 'The weapon-detection is just a fringe benefit.'

'But why no questions?'

'At the moment the Sontarans only want to know one thing about you. Are you really the carbon-based life-form you currently appear to be, or are you a cunning simulacrum produced by a mimetic, polymorphic energy-system?'

'Come again?' said Chris.

'A Rutan, dummy,' said Roz. 'Right, Doctor?'

'Right. If you're not a Rutan, the Sontarans don't want to know you. Let's keep it that way, it's a lot healthier.'

'So what do we do?'

'We just lie low and wait.'

Some time later on the Sontaran War Wheel, currently in orbit around s.p.a.ce Station Alpha, Admiral Sarg presided over another planning conference.

With his fellow Sontaran officers, Commander Steg watched as Lieutenant Vorn, newly returned from Station Alpha, marched into the conference room, crashed to attention and saluted.

'I have the honour to report that the capture of s.p.a.ce Station Alpha is complete.'

Typical of Vorn, thought Steg, to make the takeover of an unarmed commercial s.p.a.ce station sound as if he'd conquered the Rutans' home planet.

Sarg wasn't impressed either. He came straight to the point.

'Have you captured the Rutan spy?'

'No, Admiral. He is not on board the station.'

Steg sighed gustily. He had wanted to lead the expedition himself, but the High Command felt that this simple but important operation offered Vorn a chance to distinguish himself.

'You are certain of this?' rasped Sarg. 'Rutans are cunning; the spy could be concealed somewhere.'

Lieutenant Vorn was dim, but he was very conscientious.

'Every centimetre of the station has been searched with the tracker, Lord Admiral. Every life-form on the station was detected, rounded up and scanned. Most were humans and similar inferior species. Every life-form has been scanned. The Rutan is not there.'

The Admiral turned to Steg. 'Suggestions, Commander?'

'If our Intelligence agent's report was accurate ' He broke off. 'Have there been any supplementary reports?'

A communications officer said, 'None. We attempted to communicate with the agent to arrange a requested pick-up, but could make no contact.'

Abandoning the question of the vanished agent now being digested by a number of Wolverines without further thought, Steg said, 'There are only two possibilities. Either the Rutan spy is still on the s.p.a.ce station, or he is not. To cover the first possibility, the search should be renewed. If the Rutan has a.s.sumed its dormant condition it may be able to elude the trackers.'

Steg paused. 'If the Rutan left the station, we must discover the means. We need a list of every ship that departed between the spy's estimated arrival and our takeover. Every one of those ships must be overtaken and searched. A task force must be left at the station to prevent the vessels concerned being warned.'

Steg's plan was agreed. A second search of the station proved as fruitless as the first. A rapid and ruthless interrogation of the s.p.a.ce station staff produced the list of departures. Very soon a copy was in Steg's hands.

He studied it eagerly.

First name on the list was the solar yacht Tiger Moth Tiger Moth bound for s.p.a.ce Station Beta on a shakedown cruise...

The Doctor, Chris and Roz sat at a table at the back of the hall, waiting for something to happen. The Doctor was drumming on the table eyeing the ranks of Sontaran troopers, and cursing in very low Gallifreyan.

'What's the matter?' asked Chris.

'It's not like you to get so worked up,' said Roz.

'It's infuriating!' muttered the Doctor.

'What is?'

'I know,' said the Doctor. 'I just know that the Rutan is on board that solar yacht and there's nothing, nothing nothing I can do about it!' I can do about it!'

BOOK TWO.

SHAKEDOWN.

11.

Attack Sails furled, the solar yacht Tiger Moth Tiger Moth moved through s.p.a.ce looking oddly ungraceful, like an insect with far too many legs... moved through s.p.a.ce looking oddly ungraceful, like an insect with far too many legs...

Jacket slung carelessly over her shoulder, Lisa Deranne marched grimly along the ship's narrow metal corridors, Robar at her side. The very beginning of the cruise and already there was trouble.

Without speaking, Lisa strode into the control room, tossed her jacket onto a nearby console and threw herself into the command chair. Robar sat beside her in the co-pilot's seat. For the next few minutes Lisa's hands moved expertly over the controls, checking readings.

When she'd finished she looked at Robar. 'It's perfect.'

'Nope,' said Robar stubbornly. 'There's a fault.'

'Nothing shows on the checks. Nothing!'

'Comes and goes. Ever since we left Alpha One.'

' What What comes and goes?' comes and goes?'

'Power. Fluctuations at irregular intervals.'

'Which unit?'

He shrugged. 'Any of 'em. All of 'em.'

Lisa thought for a moment. It was infuriating to have engine trouble so soon, but if Robar said there was a fault...