Penley pointed to the door with the gun. 'Return to Base, Miss Garrets'

'And wait for Doomsday,' she murmured with a resigned shrug of her shoulders. She gave him one last look, then moved to the door while Penley held the screening skin to one side. For a brief moment they were out of earshot of Storr, and Penley took his opportunity quickly.

'If you still have trouble from the Ioniser,' he murmured, handing Jan back the gun, 'look up my notes on the Omega Factor. Good luck...'

He pushed her outside into the snow, and returned to the warmth of the stove. Storr was standing by it, his face unusually thoughtful.

'These aliens,' he brooded. 'They really exist, then...'

Penley was too preoccupied with his own thoughts to wonder at the fact that Storr was expressing such interest in what was, after all, a scientific supposition.

'Yes,' declared Penley firmly, shrugging on his snow garments, 'and I intend to find out more about them.' With hardly a glance back, he shuffled quickly outside, and began his uphill trek to the glacier.

Somehow, Victoria had managed to s.n.a.t.c.h a few hours of fitful sleep. Every time she had woken up, Varga had been moving from one melting block of ice to the other, almost willing the creatures inside back to life... At dawn she awoke fully, and, shivering with cold, stared towards the glacier face in numb disbelief. Only two blocks of ice remained, and these were rapidly disintegrating as the creatures inside strove to break out-almost like dragon-men from monstrous frozen eggs, she thought. Their comrades stood around them, urging them into life with a chorus of hissing. Frightened yet fascinated, Victoria began to notice the differences between them: Varga's bearing and style of helmet and reptilian armour seemed of a superior nature to the others. He seemed to delegate more and more of the physical tasks to a second-in-command-whose name, Victoria gathered, was Zondal.

He was just as gigantic in stature, but his whole aspect was fiercer and more repellent; and he snapped at and bullied the others. The remaining four warriors, including the two who had at last broken free of the ice, were less elegant and more clumsy than Varga, whose majestic bearing, seen in daylight, fitted all Victoria's ideas of a warlord. Zondal was harshly ordering the warriors into a simple formation, ready for inspection. Varga turned and, seeing Victoria crouched and awake, strode over to her.

'You see?' He proudly gestured towards his warriors. 'It has worked! All my crew are alive! The ice is our friend!'

'Then you don't need me,' replied Victoria. 'Let me go back to my own people, please!'

The Martian warlord stared at her coldly. 'You will stay here with us,' he hissed. 'If you value your life, obey-and do not anger us!'

'But I'm no use to you!' protested Victoria. 'You don't need me -you have your warriors now.'

Ignoring this plea, Varga turned and summoned his second-in-command. 'Zondal!' As the warrior approached him and saluted in the Martian fashion-clenched fist to left shoulder-Varga continued, 'You will locate our buried s.p.a.ceship without delay!'

'That will not be difficult, Commander,' came the harsh reply.

'You will then gain access to it by excavating into the glacier...' Varga paused. 'The cave that you will form will also act as an efficient trap. Proceed!'

Zondal saluted again, turned, and began to place his men at key points facing the glacier. Victoria had overheard Varga's strategy; her eyes were wide with alarm. 'But you don't need a trap. No one wants to attack you!' His grim face was implacable. She pleaded desperately. 'If you let them, they may be able to help you. You've only got to ask.'

The warlord looked down at her distraught face proudly. 'We do not need help. We are superior!'

Victoria protested, close to tears. 'You'd still be dead and frozen solid in there,' she cried out, pointing at the glacier. 'if it wasn't for us humans!'

'You are a child!' he sneered, then turned to watch Zondal organise the other warriors. Victoria wasn't going to be put off that easily.

'But what are you going to do with me?'

'A trap needs bait,' hissed the warlord. 'You will be the bait that draws your friends towards us.'

'No!' cried Victoria, in dismay. But there was no appeal against the cruel decision.

'Be silent!' ordered Varga. The violence in his voice quelled his prisoner completely. She huddled silently close to the snow creva.s.se, sullenly watching Zondal and his men.

At Varga's command, the sounding sensors on their breastplates glowed and pulsed-just as his own had done when he set out to locate his comrades. Zondal then strode forward, marked out a target area on the ice face, and gave the order.

'Sonic destructors at the ready!'

The four warriors raised their forearms in unison. The four tubular devices, pointed towards the target area.

'Set to wide impact,' Zondal paused briefly as his men made the necessary adjustments. 'Fire!' The effect of the combined sonic weapons was devastating. The ice face crazed, shattered and erupted into fragments under the impact of the invisible beams, which clawed their way deeper and deeper into the heart of the glacier. Inside minutes, the once jagged mark on the ice had been gouged hollow-then it became a cave, and still later a ma.s.sive crystalline cavern...

Victoria was not the only amazed observer. Hidden by an outcrop of frozen snow, Penley was taking in the scene from below. What the purpose of this task force was, he had no way of knowing-hut they were armed, and had a human hostage! He looked towards the girl. Rescuing her was not going to be easy. Until the opportunity arose, he could only watch, and wait...

Clent stood in the doorway of the medicare laboratory, and nodded his head in disbelief. The area that had been a.s.signed to the Doctor was no longer a neat and tidy desk unit-it was almost buried under an untidy mountain of torn and crumpled paper. And the Doctor-totally unaware of C1ent's presence-was on his knees, searching desperately for the vital sc.r.a.p of calculation... Clent moved forward until he was standing almost directly in front of the scavenging Doctor.

But he still wasn't noticed-until the Doctor came to the particular piece of paper that Clent was standing on. 'Excuse me...' he murmured, and s.n.a.t.c.hed it up. Suddenly his face broke into a broad grin. 'Ah! I thought so! Of course! Reverse the sequence and it gives a density ratio to the power of ten!'

he exclaimed gleefully, throwing his arms into the air and discarding the items that he had just been grovelling for so diligently-and at the same time seeing Clent for the first time.

'Genius at work, I see,' remarked the Base Leader drily.

'Wouldn't it be simpler if you used our computer?'

The Doctor paused in his frantic scorrving about. and, catching sight of a marker scribe in Clent's lapel, s.n.a.t.c.hed it with a smile.

'Just the thing!' he exclaimed, and started writing an extended series of calculations at shoulder height all along the nearest bare wall. Suddenly the Doctor stopped, bit his lip thoughtfully, and shook his head. 'Its not right!' he muttered.

'Somethings missing!'

At that moment, Jan Garrett entered, carrying a small sheaf of notes. She handed thetn to the Doctor. He took them eagerly.

'Your instructions were to help the Doctor, Miss Garrett,' said Clent coldly. 'Where have you been?'

'Obtaining these notes from Scientist Penley's file.'

'You had no authority-' Clent ranted. But the Doctor cut short his angry reaction with a cry of triumph.

'That's it!' he blurted out, elated. 'The Omega factor!

Clever chap, your friend Penley. Why did you ever get rid of him?'

Clent was too preoccupied with checking the formula to react to this sharp observation. As he reached the final equation, his face smiled in admiration and pride.

'It's amazing! And it was staring us in the face all the time...'

Jan hadn't the same theoretical training as Clent or Penley. She had been trained to rely on the computer for formula a.n.a.lysis. 'Will it work?' she asked Clent anxiously.

Clent quickly copied down the essential numbers. 'I'll run it through the computer myself!' the Leader exclaimed.

and hurried out, followed by Jan and the Doctor. The Doctor, turning to Jan, sighed and shook his head disapprovingly.

'It doesn't need running through a computer,' he complained, 'its perfect!' He glanced mischievously at Jan, as they hurried along the corridor leading to the control room and the computer. 'I deserve an apology,' he said, and then added, 'Penley, too. Thank you for digging out his notes.'

'I thought they might help...' murmured Jan, leading the way across to ECCO, where Clent was studying the computer print-out He was completely absorbed. his eyes glued to the machine. He made no sign of hearing the ensuing exchange between the Doctor and Jan.

'Pity Penley turned traitor...' remarked the Doctor innocently. Jan's reaction was immediate, and angry.

'He was not not a traitor! He's the most brilliant scientist we have, and if you-' a traitor! He's the most brilliant scientist we have, and if you-'

The Doctor cut her short and smiled gently. 'I'm glad he's still got some friends here at Base. I needed to know-'

'It works!' cried Clent. 'The computer says it works!'

Suddenly, the static-distorted voice of Arden crackled out from the video-communicator. The geologist's hooded face showed fuzzily on the videoscreen. and he spoke urgently.

'Glacier Task Unit to Base,' he called, 'Arden to Leader Clent. Over, over!'

Clent moved quickly to establish contact. 'Clent here, Arden. Report'

'We've arrived at the glacier site...' Arden's words faded in a sudden rush of static, then cleared again. 'There's something strange here. Can you hear me?'

'Bad atmospherics,' replied Clent, emphasising his words for clarity. 'You'll have to speak up. We'll try and boost you...' He waved a vague hand towards Jan, and she tried to adjust the controls.

'What has he found?' asked the Doctor impatiently.

'The ice face,' crackled Arden's disembodied voice. 'It's been excavated... into a sort of cave.'

'Excavated?' queried Clent.

'How?' demanded the Doctor tensely.

'Not a drill,' replied Arden, 'nor explosives... some sort of power tool, I'd say.'

'Is there any sign of a s.p.a.ce craft?' demanded Clent.

Arden's blunt answer brought them all forward, tense and expectant.

'Yes... at the back of... the excavation... there's what looks like-a metal door!'

Clent looked first at Jan, and then at the Doctor. The s.p.a.ce craft theory was right-but would its propulsion unit bring the danger that they feared?

'The place seems deserted...' Arden continued. 'But the Ice Warrior couldn't have done this... alone.'

'Don't get any closer than you need,' warned the Doctor.

'Arden, get those radiation readings quickly-and come back here at the double! Don't take any chances!'

For once, Arden didn't need Clent's warning. He shuddered as he began to set up the radiation detector, apprehension mingling with the enjoyment of discovery.

Jamie looked about, but he could see no sign of the warrior, or that Victoria had ever been here...

'We'll take the readings first, Jamie...' murmured Arden, 'and then we'll have a look round outside for Victoria. All right?' He gave the Scots lad a quick smile.

'Fair enough,' agreed Jamie. He knew the importance of the mission Clent had ordered; but he was glad that Arden shared his own feelings about Victoria.

'What readings are these, then?' he asked, as they unwound the power pack connections.

'Radiation-magnetic field-ion density... it won't take long.'

'Just as well,' muttered Jamie. 'I don't much like this place-nor that door.' He stared at it, frowning. 'I wonder what's inside it?'

Arden threw him a quick, amused glance. 'You don't think I'm leaving here until I've had a go at opening it, do you? There's never been a discovery like this before-'

They were the last words he ever spoke. At Varga's silent command, the warriors stepped out of hiding and opened fire. Victoria, her mouth smothered by Varga's mighty fist, could only watch in helpless terror as Arden took the full brunt of the ma.s.sive burst of sonic power. His body seemed to shimmer, almost disintegrate, beneath the invisible blast of energy. For a split second, he seemed suspended like a broken puppet, his face crumpled in agonised surprise.

Then he slumped to the ground beside Jamie, as though hurled there by a giant hand. The ambush complete. Varga released the girl. She stood trembling, staring at the two sprawled bodies on the cavern floor, her face wide-eyed with misery. 'You've... killed them!'

6.