'That would mean putting the TARDIS into E-space,' Nyssa said gravely. 'It would be very dangerous. The Doctor's right.'
The Doctor was walking round and round the console, his hands thrust obstinately into the depths of his pockets. 'It's another universe. It's out of the question!' he muttered.
Adric faced them defiantly. 'I could easily plot a safe course,' he argued.
The Doctor stopped in his tracks. 'We'd have to pass through the CVE,' he cried, with a mocking laugh. 'Random negative co-ordinates, young man.'
Adric shook his head. 'The Monitor on Logopolis indicated that they were compatible,' he retorted with an appealing glance at Nyssa, begging for support.
The Doctor set off round the chamber again. 'You're not as bright as the Monitor, and even if you were I am not taking you back into E-Space,' he said dismissively.
'Then I'll find someone who will take me,' shouted Adric petulantly.
'Pop outside and hail a taxi then,' scoffed the Doctor.
There was a long silence. Then at last someone spoke.
'Is it really so dangerous, Doctor?' asked a nasal Australian voice tentatively.
The speaker was a red-haired, pretty girl a little older than Nyssa, who had been listening hard and trying to follow the argument. The girl was wearing a smart purple uniform blouse and skirt and stylish shoes. She had an efficient and determined air, but at the moment she was out of her depth. Her name was Tegan.
Instead of replying the Doctor muttered something indistinct about tiresome humanoids and sublime ignorance.
Adric calmed down a little. 'Romana is still in E-Space,' he said. 'Once I've calculated the course I'm sure she'll help me. Can I borrow the computer, Doctor?'
The tall figure waved his arms despairingly. 'Help yourself, Adric,' he muttered quietly, crossing to the console and busying himself with making adjustments to the TARDIS's complex navigational instruments. 'But don't expect the rest of us to wait around while you compute your own destruction...'
The Doctor's grim warning seemed to cast a chill in the air and Tegan and Nyssa exchanged concerned glances as Adric went over to the computer panel and eagerly set to work.
As the taskforce led by Lieutenant Scott penetrated deeper and deeper into the mountain, the going had grown steadily tougher and they had reached a section of low narrow tunnel which forced them to crawl painfully forward on their stomachs.
'Are you sure this is the only way down?' Scott panted in the stale clammy air, mopping his streaming face.
Professor Kyle nodded, gulping gratefully from Sergeant Mitchell's proffered water flask and hoping no one would notice her trembling hands. 'We had problems right from the start,' she gasped, trying unsuccessfully to sound casual. 'Tools disappearing. Then vital equipment mysteriously smashed. Things like that.'
'Sounds like sabotage to me,' Scott said loudly. 'Nothing mysterious about that.'
Professor Kyle wiped her scratched, dirty face with her rough sleeve.
'Sabotage? But who? Why?'
'What was that?' Scott murmured, suddenly turning his head and directing his twin helmet lights along a gully leading off at right angles from the main tunnel.
'Something seemed to move.'
The squad stirred uneasily, following Scott's powerful beams with wary eyes, their laser tubes poised to fire.
'Nothing there now, sir,' Sergeant Mitchell said after a hushed pause.
Scott shook his head as if to clear his vision. 'I'm sure something moved down there,' he insisted, with a long searching look at Kyle. She shrugged and said nothing.
They waited in the oppressive silence broken only by echoing drips.
Eventually Scott motioned Professor Kyle to lead onward. After they had crawled for several hundred metres the tunnel widened and grew higher again. The taskforce pressed on, crouching and slithering precariously over the treacherously uneven and slippery floor. They had not gone far when the tunnel lighting suddenly flickered several times and then went out completely. Shouts of alarm and then a piercing scream rang out. A weird electrical crackle buzzed in the air and after a few seconds the faint lights came on again.
Scott slithered across the tunnel to an injured female trooper who was lying moaning in agony, her body unnaturally crooked and her face streaked with blood.
'I'm sorry, Lieutenant. It's my shoulder...' she gasped, as two troopers came to her aid.
Scott flicked on his radio, called up Walters and Snyder and told them to prepare to receive a casualty on the surface.
As he spoke, the communicator was suddenly flooded with harsh static. The tunnel lights flickered uncertainly and the air was again filled with the strange buzzing.
'What's going on down there?' Walters' voice broke faintly through the interference. 'The scanner's flaring like crazy up here.'
'See if you can get a fix on the source,' Scott ordered.
'It seems to be right next to you, Lieutenant,' Walters reported excitedly, 'but I can't get anything from the computer. It doesn't seem to register the flaring at all.'
Scott glanced at his squad. Some of them had removed their helmets and were touching their hair in amazement as they received a very mild kind of electric shock.
'The flare's disappeared now, sir,' said Walters as the static noise faded and the tunnel lights stopped flickering.
'Damn!' Scott muttered. 'If only we could get a fix on whatever's causing it...'
Professor Kyle had been clutching Sergeant Mitchell's arm and staring wildly about her. She was trembling and her lips moved, but at first no sound emerged. 'That
noise...' she managed to whisper eventually in a haunted voice, 'I remember now... I heard it just before...'
'When?' Scott demanded.
Kyle shuddered, as if she were recalling some terrible nightmare from the past.
'Just a few seconds before we were attacked...' she blurted out in a choked voice.
Deeper in the dark labyrinth a strange commotion suddenly disturbed the deathly silence. A harsh scraping and whirring noise was accompanied by a shivering in the rock walls as a faint blinking yellow light appeared. It grew brighter and brighter, and with a final series of raucous shrieks a battered blue police box materialised, faded, reappeared and fell silent. The darkness seemed to gather itself like a dense cluster of swirling black drapery and then to settle itself to wait . . .
Inside the brightly lit control chamber of the TARDIS the Doctor gave the time-warp anchorage unit a final pat to encourage stability and flashed a smile of satisfaction at his three young companions. 'Here we are again!' he announced in a jaunty tone.
'Where?' demanded Tegan, exchanging sceptical glances with Nyssa.
'Earth, of course. Where else?' the Doctor replied blandly. Nyssa's fine features wrinkled with disappointment. 'Not again,' she sighed.
'Twenty-sixth century,' Adric murmured, frowning at the computer. 'AD 2526
actually,' he added helpfully for Tegan's benefit.
'Not a bad vintage at all,' remarked the Doctor cheerfully, operating the switch to raise the shutter covering the external viewer screen.
'Why Earth?' Nyssa asked disapprovingly.
'Why on earth not?' the Doctor joked, studying the viewer with childlike pleasure. 'Adric wants to use the computer, I want to take a little walk.'
'In the dark?' Tegan exclaimed, pointing unenthusiastically at the screen.
'Doctor, since your regeneration you've become decidedly immature,' Adric remarked acidly without looking up from his calculations.
The Doctor's mild face abruptly clouded with rage and for a few dangerous moments it looked as though he would erupt. Controlling himself with great difficulty he operated the external door lever. Then he reached into his pocket and drew out what looked like a parchment scroll tied with a scarlet ribbon. With a deft flicking movement he unrolled it and shook it into shape. It was a flexible straw panama hat with a red band. With exaggerated dignity the Doctor put it on his head. He strode to the open door and turned. 'I might be back...' he said haughtily and then stalked outside.
For a moment no one spoke. Then Tegan walked quietly out after him.
'It's all got rather silly, hasn't it?' Nyssa said loftily.
'I didn't mean to be so rude,' Adric mumbled shamefacedly.
Nyssa went over and put her arm round his shoulder. 'When you've completed your calculations we'll show them to the Doctor,' she said encouragingly. 'When he's calmed down I'm sure we'll be able to persuade him...'
Adric worked away in silence for a few seconds and then looked up gratefully.
But Nyssa had gone. He was quite alone.
Trooper Walters brushed the sweat from his eyes as he concentrated on the softly glowing monitor. Two fluorescent spots representing the wounded trooper and her escort returning to the surface were moving laboriously in one direction, while a tight cluster of eleven dots showing the painful progress of the taskforce moved slowly the opposite way, deeper into the mountain.
Suddenly three new pinpoints appeared one after another to one side and a short distance ahead of the advancing squad. One of the new blips was pulsing oddly.
Walters stared at it intently and then gasped in astonishment.
'What is it?' Snyder said, running over to the scanner.
Walters flicked on his radio. 'Lieutenant Scott – three unidentified mammalian life-forms just registered in your vicinity,' he rapped, 'and I know it's impossible, sir, but one of the blips is ectopic.'
'Meaning what?' crackled Scott's voice impatiently.
There was a short pause while Walters glanced at Snyder.
'Meaning that... that one of the sources must have two hearts!' Walters replied uncertainly.
There was another pause. The radio crackled and hissed.
'Have you been drinking, Walters?' Scott demanded.
Trooper Snyder leaned over and confirmed the scanner observation while Walters ran a rapid series of computer checks.
'The computer confirms it, sir,' Walters reported at last.
'Aliens!' Scott's metallic voice rang out eerily against the cliff.
'At least one, sir.'
'Quick, give me a fix on them,' Scott snapped.
Walters read off a long string of co-ordinates from the computer and then listened while Scott and Kyle conferred.
Then the Lieutenant spoke hurriedly. 'Listen, Walters, the Professor estimates that the alien, or aliens, or whatever, must be in one of the fossil caves near where she and her team were attacked. We're going in right now. Keep your eyes on that monitor.' The radio clicked off.
There was silence and then Snyder jabbed her finger at the two lonely blips struggling towards the surface. 'I don't like it. They're hardly moving,' she murmured, unhitching her laser tube. 'I'm going down to help...'
Before Walters could object, the dumpy little figure had been swallowed up by the dark maw gaping hungrily at the foot of the vast cliff.
Guided by Walters via the radio, Trooper Snyder crept quickly along the dimly lit tunnels to rendezvous with the wounded trooper and her escort. Every so often she stopped to listen and thought she heard their scuffling steps somewhere in the gloomy honeycomb ahead, but her tentative calls received no response. Eventually, as she emerged from the low narrow section and scrambled to her feet, she heard a faint voice.
'Is that you, Snyder?' it called.
'Yes. Wait there for me,' she shouted thankfully, quickening her pace.
'Who's that with you?' cried the voice.
Snyder stopped dead. She tried to shout that she was alone, but her throat had shrunk tight and her lips felt dry as dust.
At that moment Walters' voice burst through a mush of static on her receiver.
'You're very close now, Snyder, but there's a lot of flaring near you. Can you see anything yet?'
'Nothing,' she managed to croak. She tugged off her helmet and felt her hair suddenly bristle in the fizzing air.
'The flare's increasing and it's getting closer to you,' Walters hissed barely distinctly, 'but it's just like last time, I can't get a reading on the computer...'
'Snyder!' yelled the voice from along the tunnel. 'What are you two playing at?
You're both ... You're...' The words stretched out into a long series of shrill, bloodcurdling screams, and then there was silence.
For several seconds Snyder was rooted to the spot. Then she started to run towards the terrible sound, charging and priming her laser as she ran. Rounding a corner, she came upon two dim shapes standing in the shadows. She froze. Then a relieved laugh burst from her. 'You really scared me,' she cried, 'I thought you were...'
'Snyder . . . Snyder come out of there . . . They're both dead,' Walters was screaming from the radio. 'That flare just wiped them out and now it's right on top of you. Come back...'
Something splashed over Snyder's boots. Tearing her eyes away from the two ghostly apparitions, she glanced down. What she saw made her stomach fly up into her throat. She was standing in a shallow pool of steaming, viscous liquid in which were floating the scorched and tattered uniforms of two troopers. A sickly smell hung in the crackling air.
Snyder tried to back away, fumbling with her laser as she stared mesmerised at the two black mummy-like figures, their polished, featureless faces watching her and their left arms slowly rising to point accusingly at her. The tips of their outstretched hands suddenly exploded in a searing flash. Snyder's empty uniform collapsed into a puddle of sticky oozing froth and floated beside her radio while Walters' panic-stricken pleas broke intermittently through the static.
The two shadows waited motionless for a moment, as if listening to Walters'
desperate, disembodied voice. Then they spun round and darted silently away towards the interior.