When Toba and his cohort of Quarks reached the fourth perimeter target near the gorge, Baran was still lying dazed by the rig. Toa yanked him to his feet.

'A Quark has been destroyed, another damaged. Who was responsible?' he hissed.

The frail Dulcian whimpered helplessly. Toba shook his victim like a bundle of sticks. Baran stared like a terrified animal. 'I did not see... I was working... I was almost hit...'

he pleaded.

The Quarks had formed a circle round the rig and were scanning the area with wickedly slicing antennae.

'Evidence of alien a.s.sault,' one of them squawked.

Toba gripped Balan's stick-like arms mercilessly. 'Is there a resistant force on this Island?' he demanded hopefully.

'There is no force on Dulkis,' Baran answered feebly.

The Dominator flung the old man aside and gazed around, his green, red-rimmed eyes alight with malice. 'Quarks, search the Island. Destroy any alien specimens not accounted for. Total destruction!' he raved, his huge nostrils flaring hideously. Having ordered a Quark to escort Baran back to the saucer, he marched away to the central bore target by the ruined museum.

There, Kando and Teel still laboured to clear the remaining debris under the relentless surveillance of a pair of Quarks.

'Perimeter four has been attacked and a Quark eliminated,' Toba spat, stamping up to them.

Kando turned excitedly to Teel. 'Kully must have...'

Too late her she bit her lip and blushed.

Toba seized her by the hair and twisted viciously. The willowy girl folded like a wounded gull. 'What do you know about this?' Tuba screamed.

'Leave her...' Teel blurted out, wielding a metal strip.

Dropping Kando, Toba turned on the youth. 'Do you dare to defy a Dominator?' he challenged in an awesome whisper.

Suddenly Teel hurled himself forward, flailing uselessly at the enormous armoured figure standing over the pale, quaking girl.

Toba did not move, but merely gloated with creaking grunts of pleasure as Teel battered vainly against his plated chest. Eventually, the Dominator tired of the game as his a.s.sailant's slim arms quickly weakened.

'Quark. Restrain!' he commanded.

One of the robots advanced on Teel, opening its probes like a pincer.

'No!' Kando gasped, scrambling up.

Toba seized her wrists and shook her like a dish cloth.

'No one ever questions a Dominator,' he rapped.

The Quark caught Teel round the waist and lifted him effortlessly off the ground. Then it tightened its grip and Teel almost folded in half.

'Stop. Please stop!' Kando cried, hanging limp from Toba's gloves.

'Power!' Tuba ordered.

There was a dull cracking sound and Teel uttered a long hollow moan of agony.

'Stop. I'll tell you...' Kando shrieked.

'Release!' commanded Toba.

The Quark immediately opened its probes and Teel dropped to the sand, writhing silently.

'Who attacked my Quarks?' Toba demanded, thrusting his face into Kando's as he raised her level with him.

'It... it must have been Kully.'

'The specimen Kully is destroyed,' retorted Toba, twisting Kando's slender wrists in opposite directions. She struggled to speak, but the excruciating pain paralysed her throat.

Then the Dominator's emerald eyes shrank into tiny brilliant points. 'The other boy... the stupid one. He must be responsible.' he hissed. 'Where is he?'

Kando shook her head and then closed her eyes, waiting for the end. But her tormentor suddenly released her and she slumped at his feet, huddled and trembling.

Toba loomed or his two victims, as if he were about to crush them out of existence. 'One of you must know where the stupid one is,' he breathed at last.' And you will tell me...'

The Doctor only just had time to replace the inspection panel in the dais when the Quark drove Balan into the control centre. While the robot went over to monitor the bore-project display, the Doctor and Zoe managed a furtive conversation with the exhausted Educator. Zoe was overjoyed to hear that Jamie had probably destroyed another Quark and damaged a third. Despite Balan's condition, the Doctor plied him with whispered questions in an attempt to solve the mystery of the drilling operations.

'Balan, when the Dulcian scientists exploded the atomic device on the Island all those years ago... where did they obtain the fission material?'

Balan cast his clouded mind back as best he could. 'I believe that their requirements came from somewhere in the northern hemisphere...'

'The other side of the planet. Then why are the Dominators drilling here?'

Balan shrugged wearily. 'Perhaps because the planet's crust is very thin just here.'

The Doctor slapped himself on the forehead. 'The magma!' he gasped, turning to Zoe. 'The molten planetary core...' He turned back to Balan. 'Could the magma be radioactive?'

The Educator looked uncertain. 'The minor eruptions which occur here from time to time have never registered such radiation, Doctor.'

'But are we sure these Dominator, are drilling for fuel?'

Zoe interjected.

The Doctor gestured at the schematic display in front of the Quark. 'It's the pattern that intrigues me, Zoe,' he murmured. 'Four drill holes arranged in a square, with a fifth hole where the diagonals cross in the centre...

fascinating...'

Zoe squinted across the chamber at the project display.

'I think that fifth hole is the one by the ruin, Doctor: The Doctor nodded. 'The bull's-eye...' he murmured.

At that moment Probationer Toba burst in followed by the Quark with Kando and Teel. The latter was stumbling, doubled over with both arms clutched across his chest.

'Quarks, a.s.semble the specimens,' ordered Toba.

The two robots herded Kando and Teel next to the Doctor, Zoe and Balan. Zoe tried to help Kando support the injured Teel, but they were brutally shoved apart.

Toba walked slowly round the frightened huddle. 'The other simpleton the boy is missing,' he rasped. 'He has defied the Dominators and attacked the Quarks. Where is he?'

There was a long silence. Zoe glanced anxiously at the Doctor. Balan gazed in horror at Kando and the semi-conscious Teel.

Toba walked round them again, his vast hands clenching and unclenching with an ominous squeaking.

'You will die, one by one, until you inform me...' he tormented them.

Still there was silence. Toba stopped and jabbed his creaking glove at Balan. 'You were a witness. Speak.'

The Educator stared mesmerised into Toba's glittering eyes.

The Dominator stepped hack. 'Quark, destroy!'

One of the robots whirred expectantly. Kando cried out and clung convulsively to Teel. A sizzling bolt tore through the air and Balan's protective suit collapsed in a heap, empty.

Striding over it with savage indifference, Toba towered over the Doctor. 'You know the simpleton boy. Where is he? Answer or die.'

The Doctor hesitated, fiddling nervously with his tie and blinking meekly. Then his eyes narrowed and he curled his lip in disgust and contempt. But he remained silent.

Zoe held her breath, watching the Doctor's struggle to contain his outrage with anxious admiration.

'Answer!' hissed Toba.

The Doctor compressed his lips and set his jaw.

Something in his eyes seemed to disconcert the Dominator, something he had not antic.i.p.ated.

After a brief duel of wills, Toba turned abruptly and lumbered away a few paces. 'Quark!' he rapped.

The nearest Quark jerked its probes round towards the Doctor and waited, its antennae glowing red and its circuits clattering in growing excitement.

Zoe thrust her fist into her mouth and shut her eyes...

9.

Last Chances Jamie and Kully had managed to escape from the gorge by the skin of their teeth after the damaged Quark, hard on their heels, had suddenly ground to a smoking halt halfway up the slope, its traction mechanism finally burnt out, but its probes still firing intermittently. As they dragged themselves dazed but unharmed onto the plateau above, they found their escape cut off. A huge crescent of Quarks was advancing towards them, driving them relentlessly back into the gorge.

'Where did all yon tin Sa.s.senachs spring from?' Jamie exclaimed, pulling Kully down into a hollow just in time to avoid the vicious crossfire of ultrasonic pulses which suddenly shredded the air above them.

A stinging torrent of sand erupted a few metres away and fell on them, almost completely burying them. Jamie wriggled furiously to and fro, working his way in a kind of trench towards the steep cliff edge.

'Come away, Kully!' Jam yelled above the sizzling din.

'Let's get to the shelter and lie doggo till things cool down.

wee bit.'

'Doggo?' Kully echoed, spitting the sand our of his mouth and trying to imitate Jamie's ample.

With a series of deafening roars, several more huge columns of sand shot into the air and scattered around them. Jamie turned himself round and grabbed Kully's flailing hands, and hauled the squirming Dulcian towards the steep drop.

'Come on, they're far too close for comfort!' Jamie panted, heaving Kully's sweating hulk through the trench.

When the exhausted Dulcian reached the precipitous edge, he went rigid with terror. Without thinking, Jamie rolled himself over the cliff and dragged Kully after him...

Half rolling and half sliding down the brittle sandstone face, they soon reached the dunes below. Then, after a hair-raising skirmish with a Quark patrol advancing from the direction of the saucer, they eventually reached the deserted ruin.

Bundling Kully through the hatch into the atomic shelter, Jamie searched frantically around in the wreckage until he located the tip of the periscope mechanism. After a brief struggle, he managed to clear away the obstruction that was preventing it extending properly. Nearby, he came across the blocked inlet for the ventilator system and soon dislodged enough sand to allow at least some air through into the shelter below. Then he took cover.

Squeezing himself through the hatch, Jamie carefully lowered it shut after making sure that no loose debris could jam it again. He found Kully lying on one of the bunks.

'That was marvellous fun,' Kully panted, 'especially the avalanche.'

'Aye, we fair stirred them up,' Jamie chuckled, getting his breath back. 'We'll lie low a wee while and keep 'em guessing. Then we'll oot and bag another Quark or two.'

Just then his stomach rumbled noisily. 'Och, I'm fair starving,' he grinned.

Kully patted his own ample belly. 'Fighting is hungry work,' he agreed cheerfully. Levering himself off the bunk, he began to rummage in a small locker unit underneath it.

With a whoop of triumph he stood up brandishing a slim bar wrapped in toil. Tearing off the wrapper, he broke the bar in half and handed Jamie a piece of a grey waxy substance.

Jamie sniffed at it unenthusiastically. 'What's this stuff?'

'Basic nutrients,' Kully explained, cramming his portion into his mouth and chewing greedily. 'Proteins, vitamins, carbohydrates. You can survive on it for annos.'