DOCTOR WHO AND THE INVISIBLE ENEMY

by Terrance Dicks

  A mysterious cloud drifts menacingly through space...

  A sudden energy flash and the Doctor is infected with the Nucleus of a malignant Virus that threatens to destroy his mind.

  Meanwhile, on Titan, human slaves prepare the Hive from which the Virus will swarm out and infect the universe.

  In search of a cure, Leela takes the Doctor to the Foundation where they make an incredible journey into the Doctor's brain in an attempt to destroy the Nucleus.

  But can the Doctor free himself from the Nucleus in time to reach Titan and destroy the Hive? Luckily he has help - in the strangely dog-like shape of a mobile computer called K9...

  ISBN 0 426 20054 3

  DOCTOR WHO

  AND THE

  INVISIBLE ENEMY

  * * *

  Based on the BBC television serial The Invisible Enemy by Bob Baker and Dave Martin by arrangement with the British Broadcasting Corporation

  * * *

  TERRANCE DICKS

  published by

  The Paperback Division of

  W. H. Allen & Co. Ltd

  A Target Book

  Published in 1979

  by the Paperback Division of W. H. Allen & Co. Ltd.

  A Howard & Wyndham Company

  44 Hill Street, London W1X 8LB

  Copyright © 1979 by Terrance Dicks, Bob Baker and Dave Martin

  'Doctor Who' series copyright © 1979 by the British Broadcasting Corporation

  Printed in Great Britain by

  Richard Clay (The Chauncer Press) Ltd, Bungay, Suffolk

  ISBN 0 426 20054 3

  This book is sold subject to the condition that it shall not, by way of trade or otherwise, be lent, re-sold, hired out or otherwise circulated without the publisher's prior consent in any form of binding or cover other than that in which it is published and without a similar condition including this condition being imposed on the subsequent purchaser.

  CONTENTS

  1 Contact

  2 The Host

  3 Death Sentence

  4 Foundation

  5 Counter-Attack

  6 The Clones

  7 Mind Hunt

  8 Interface

  9 Nucleus

  10 The Antidote

  11 The Hive

  12 Inferno

  1

  Contact

  Something was waiting out in space.

  It drifted between the stars, formless, shapeless, a hazy, drifting cloud, waiting patiently, as it had waited for millennia. It was helpless since it lacked physical form, yet potentially it was all-powerful. Apparently inert, it was filled with life and a fierce, driving purpose. It was waiting for a host.

  The space shuttle nosed its way through the asteroid belt, altering course to avoid the larger ones, deflecting the smaller with its energy shields. Inside the little control cabin, the bored three-man crew waited for the long voyage to end.

  Meeker was at the controls, staring moodily at the instrument panels. Behind him the captain, Safran, and Silvey, the other crew member, lay on their acceleration couches. Safran was dozing, his worn features relaxed in sleep. Silvey, young and fresh-faced, was awake and restless.

  Technically, Meeker was on duty, though in reality he had nothing to do. A steady, self-satisfied instrument-beep announced that the ship's computer was really in charge. It had brought the ship from Earth, soon it would land it safely on Titan, one of the ten moons that circled the giant planet Saturn, 1,430 million kilometres from Earth's sun. This was the paradox of space travel. You selected the brightest, the most determined from thousands of candidates and trained them to a peak of mental and physical skill. Then you surrounded them with computer technology so that only in some million-to-one emergency would their skills ever be needed.

  The space radar screen was filled with the blips that marked the track of the asteroids. A particularly large one appeared; the ship tilted in an emergency course-correction.

  Meeker decided to stage his own little rebellion. His hands moved over the controls. Silvey looked up. 'What are you doing?'

  'Going over to manual.'

  'What for?'

  'Why not? If I'm going to be banged around, I'd sooner do it myself!' Meeker flicked on the forward scanner and began steering a course through the asteroids, throwing the little ship about in his enthusiasm.

  Silvey yawned. 'It's still telling you what to do...'

  'Yes, but at least I'm doing it!'

  A sudden lurch nearly sent Silvey from his acceleration couch. 'Oh, come on, Meeker...'

  A second, and even more violent lurch produced a steady, reproachful beep from the watchful computer. Captain Safran opened one eye. 'You're off course, Meeker.'

  Meeker wrestled with the controls. 'Sorry, Skipper.'

  'Put it back on automatic, Meeker—please.'

  Still struggling to complete his course correction, Meeker muttered, 'I can't...' He felt a sudden flare of panic as the computer failed to respond. It was as if something had distracted its attention.

  Safran got to his feet, leaned over the console and stabbed rapidly at the controls. The alarm signal ceased, there was a musical beep, and the controls locked back on to automatic.

  Safran said, 'Titan shuttle captain to computer.'

  A musical tone acknowledged his self-identification. 'New course for Titan, please.'

  A beep of assent. Lights flashed on the keyboard,.and the shuttle adjusted its course.

  Safran put a hand on Meeker's shoulder. 'All right, Meeker, that's enough. You're off watch. At once, please.'

  Meeker took Safran's place on the couch, while Safran slid easily into the command chair. Automatically he began checking his instruments.

  The shuttle was almost through the asteroid belt by now, and the drifting cloud was waiting. As the shuttle approached, the cloud flickered with energy, as if it sensed the presence of approaching life. It thickened, condensed, and began moving purposefully towards the shuttle.

  Safran said reproachfully, 'You've lost us three minutes, Meeker!'

  'So? Going to be there six months, aren't we?'

  'That's not the point! '

  'Sorry, Skipper. The thought of six months on Titan...'

  'What's wrong with it?' asked Silvey cheerfully. 'Routine duties, easy life...'

  Meeker nearly exploded. 'I qualified for exploration eight years ago, and what am I? Glorified garage attendant on a planetary filling station!'

  Silvey grinned sympathetically. Actually there was some point to Meeker's complaint. But Space Service rules were strict. Everyone had to accept his share of the routine duties, as well as the more exciting and glamorous assignments.

  'Your turn'll come,' said Safran consolingly. 'And you'll be glad enough of refuelling bases then.'

  Meeker refused to be consoled. 'All I'm saying is why take a real space pilot and—'

  An alarm-beep from the computer interrupted him.

  'Unidentified organism approaching,' said the computer. 'Changing course to avoid.'

  The shuttle veered away from the approaching space cloud. But as it brushed the edge, something within the nebulous mass flared into life, and sent out a fiery tentacle. Lightning flickered around the shuttle for a moment, then died away.

  The shuttle moved on, and the cloud began drifting away through space...

  Safran stared at the empty radar screen. 'What was all that about? There's nothing there... Titan shuttle captain. Report please.'

  In a slurred, dragging voice the computer said, 'Contact has been made...'

  Safran looked at his two crew members. 'Contact?' he said wonderingly. 'What does that mean?' No one answered him.

  Meanwhil
e another craft was on its way to the same remote edge of the solar system, travelling through the vortex, that mysterious region where space and time are one. It was called the TARDIS and the outside of it resembled an old blue police-box. The inside was a very different matter. The TARDIS was dimensionally transcendental—bigger on the inside than the outside. How much bigger was difficult to say, but an astonishing number of rooms were tucked away inside.

  A very tall man with a mop of curly hair marched into one of the control rooms and stood gazing around with an expression of mild displeasure. He was dressed with a kind of casual Bohemian elegance in a long, loose jacket, gaily checked waistcoat and tweed trousers. The outfit was topped with a broad-brimmed soft hat, and an incredibly long multi-coloured scarf dangled round his neck.

  The girl who followed him into the control room wore a brief outfit made from animal skins. She moved with panther-like grace and her hand was never far from the knife in her belt. Leela had been brought up as a fighting warrior in a tribe that had regressed from technological civilisation to primitive savagery. She had been the Doctor's companion for some time, and she should have been used to scientific marvels by now—but the TARDIS could still surprise her.

  Leela gazed wonderingly around the control room.

  It seemed very like the TARDIS control room she was used to, the same many-sided console in the centre. But there was one major difference. This control room was all in gleaming white. Leela looked at the Doctor. 'We've never been here before.'

  'You've never been here before,' said the Doctor moodily. He crossed to the console, removed a side-panel and began checking something inside.

  'Where are we?' asked Leela curiously.

  'Number two control room. It's been closed for redecoration.' The Doctor glared at the console. 'I don't like the colour,' he said accusingly.

  'White isn't a colour,' objected Leela.

  The Doctor said, 'That's the trouble with computers, always thinking in black and white. No aquamarines, no blues. No imagination!'

  Leela gathered that the TARDIS had the power to redecorate itself on its own initiative. She was about to ask the Doctor why he didn't just order the redecoration to be changed, when the control room gave a sudden lurch. 'Have we stopped?'

  'No, we haven't stopped.'

  'Have we materialised?'

  'Yes.' The Doctor flicked on the scanner. Somewhere in the distance a huge planet hung in space. It was surrounded by a shining ring, a kind of halo.

  Leela looked at the screen. 'Where are we, Doctor?'

  The Doctor studied instrument-readings. 'The edge of Earth's solar system, somewhere near Saturn... about 5,000 AD.' He looked at Leela. '5,000 AD, Leela! We're in the time of your ancestors.'

  'Ancestors?' Leela's tribe, the Sevateem, were the descendants of a planetary survey team who had been stranded on a hostile planet.

  ''That's right. That was the time of the great break-out!'

  'The great what?'

  The Doctor stared abstractedly at the ringed planet on the scanner. 'The time when your forefathers went leapfrogging across the solar system on their way to the stars. The asteroid belt's probably teeming with them by now. Frontiersmen, pioneers, waiting to spread across the galaxy like a tidal wave—or a disease...'

  'Why a disease—I thought you liked humanity?'

  'I do, I do,' protested the Doctor. 'Some of my best friends are human. But when they get together in great numbers, other life-forms sometimes suffer...'

  Saturn is a giant of a planet, an immense globe of gas seven hundred and fifty times the volume of Earth. Besides its famous 'rings', formed by countless icy particles reflecting the dim sunlight, Saturn is celebrated for the number of its moons. There are ten in all, and the largest, Titan, is the biggest satellite in the solar system. Larger than the planet Mercury, it has its own cloudy atmosphere of hydrogen and methane. It was on Titan that the Earthmen had built their refuelling base. Giant fans sucked the hydrogen/methane atmosphere through enormous intake shafts, into the station's storage tanks where it was processed and converted into chemical booster fuel. The station itself was bleakly functional, its machinery and living quarters embedded deep in solid rock. It was a place of winding tunnels and metal corridors festooned with miles of sprawling gas-pipes. Here the crew of the shuttle craft were to live, or at least exist, for the next six months, relieving the three-man crew already there.

  The space shuttle drifted into the station docking bay and locked on, the whole operation master-minded by the computer. There was a clang and a hiss as the ship's airlock connected with the tunnel that led into the base.

  In the control cabin the computer said, 'Docking complete. Ship locked-on.'

  The three crewmen were pulling on their helmets and space gauntlets, moving in uncanny unison, as though under the direction of a single mind. Safran went over to the arms locker, and took out three hand-blasters. He passed two to Meeker and Silvey, and kept the third for himself. He slipped the blaster into the thigh-pocket of his space-suit and the others did the same.

  Safran led them to the airlock door and swung it open.

  They moved through the little tunnel, Safran opened another door and they emerged into a metal corridor.

  A cheerful voice came from a near-by loudspeaker. 'Are we glad to see you! Welcome to Titan—and you're welcome to it!' The voice paused as if expecting some answer. Safran, Meeker and Silvey stood motionless, waiting. The only sound was the strangely hoarse breathing from beneath their helmets. After a moment, the voice went on, 'Well, we're all in the mess, celebrating. Come and join us.'

  The corridor led to a wider one, broader and better lit, and that in turn led to an open area with two metal doors. One was marked Crew Mess Room. From behind it came laughter and a babble of cheerful talk. The soon-to-be-relieved crew were celebrating their departure. Safran moved to the other door and opened it. Sleeping quarters, neat and empty, blankets folded, a bulging travel-pack on the end of each bunk. The Titan crew were packed and ready to go.

  Safran closed the door and moved back to the mess. He drew the blaster from his pocket, and the two others did the same.

  He touched a control-plate and the mess-room door slid open.

  2

  The Host

  The departing crew were celebrating with a final dinner. Food-packs and drinks flasks littered the crew-room table. As the door opened, their captain stood up, three wine-filled beakers in his hands. 'There you are! Come on in and join the party.'

  Three space-suited figures stood motionless in the doorway, their faces invisible behind dark helmet-visors. Uneasily, the captain said. 'Come on, get your gear off and relax. You're going to be here for another six...' His voice tailed off, as Safran raised his blaster. 'Hey, what kind of a joke is...' There was a sudden crackle of blaster-fire and the captain's body was hurled backwards. As the other crew members jumped to their feet, Meeker and Silvey shot them down. When the noise and the cries died away, three dead bodies lay sprawled across the room.

  'There will be one other,' said Safran. 'The station supervisor. We must find and destroy him. Then we can make this the ideal place in which to breed and multiply.' As he spoke, Safran was taking off his helmet. A shining, metallic rash was spreading over his face, thickening the eyebrows and altering the skin around the eyes.

  Meeker and Silvey showed no surprise. When they took off their helmets, the same rash was on their faces too. The crew of the Titan shuttle were no longer entirely human.

  The supervisor's office was the nerve centre of the base. It held lockers, a wall map of the base, and master controls for the various storage tanks.

  The station supervisor's name was Lowe, and he was a fussy, methodical man. He sat in his office, nursing his injured pride. Regulations were quite specific. On arrival at the refuelling base incoming crews report to the station supervisor. Naturally enough, most stopped off for a word with the crew they were replacing. But he'd allowed plenty of time for that, and the
y really should he here by now.

  Lowe touched the switch that would send his voice all over the base. 'Shuttle relief crew, this is Supervisor Lowe. Please report to me immediately.' There was no reply.

  Lowe flicked irritably at the controls of the visiphone on his desk. Maybe they'd been delayed on the ship. He punched up a view of the air-lock corridor on the little screen. Empty. They must be off the ship by now. No doubt they were still drinking in the mess. Lowe switched channels—and found himself looking at a room full of dead bodies. He gave a gasp of horror. 'My God, what's happened?' With trembling fingers he fumbled at the visiphone controls. A space-suited figure appeared on the screen, walking down the corridor towards him. 'What is it?' shouted Lowe. 'What's gone wrong?'

  The figure paused, then moved to the lens. Its face filled the screen. 'Wrong? There is nothing wrong. This place is most suitable for the Purpose.'

  Lowe peered at the screen. Surely that was Safran? But there was something wrong with his face, and the voice... 'What purpose? Safran, is that you? What's happened?'

  'Who is this—Safran?' asked the slurred, inhuman voice.

  Horrified, Lowe switched to the corridor outside his office. Two figures were moving towards him. They had blasters in their hands, and their faces showed the same inhuman distortions as Safran.

  Lowe hurried to the door and locked it. He opened a panel in his desk to reveal a high-powered space radio, and pressed a red button marked 'Distress Call'. The transmitter started giving out a high-pitched, urgent beep. 'Mayday, Mayday, Mayday,' said Lowe urgently. 'This is Titan Base. Mayday, Mayday, Mayday.' He switched the transmitter to record and repeat, crossed to a locker and took out an emergency space suit. He pulled the locker away from the wall, revealing a circular hatch. Quickly Lowe began climbing into the suit.