'But why? What are you going to do?' Jamie demanded.

'No time to explain now,' the Doctor cried, pushing his way through them to the periscope. 'Ah good, coast's clear at last' He at scrambled up the mound of sand under the trap-door, clutching the seeding trigger under his arm like a rugby ball.

Kully tried to get up. 'But you must come with us to the Capitol. My father will want to see you...'

'So sorry. Some other time. Got to dash...' The Doctor planted his head against the hatch and pushed it open with a crash.

'On behalf of the Dulcian crommunity...' Teel began, standing up with shy solemnity.

'Apologies. Not now. Compliments and so on to the esteemed Council...' the Doctor waved.

A moment later he was gone.

There was a stunned silence.

'Where's he gone?' Zoe asked at last.

Jame shrugged. 'Och, we'll just have to do as he says. I hope he's not up to anything too daft though...'

Inside the giant saucer, the Dominators were completing final preparations for firing the perimeter rockets and for immediate take-off from Dulkis. The control centre hummed and flickered with intense activity.

'Remaining Quarks about to board,' Toba reported.

'Particle flux?'

'Confirmed.'

'Good. Perimeter targets primed,' Rago checked.

'Seeding trigger in situ in situ. Approaching criticality minus alpha,' Toba warned.

'Affirmative. Target projectile and take-off countdowns locked in sequence.'

At that moment, beneath the ma.s.sive craft, a dapper figure was scurrying breathlessly up behind the last Quark as it entered the elevator at the foot of the central shaft.

Just as the access panel began to close, the figure took something out of his coat and placed it carefully on the floor of the cubicle behind the robot.

'Just a little something for the journey...' he murmured, jumping back in the nick of time as the hatch clicked shut.

Then he turned and ran away across the dunes as fast as his short legs would carry him.

High up in the control centre, Toba was monitoring the flight displays. 'Propulsion flux at optimum,' he announced.

'Initiate take-off,' Rago ordered.

A colossal shudder ran through the saucer as it wobbled and then began to rise slowly from the sand.

'Target rockets fired. All maximum penetration...' Rago reported with satisfaction. 'Seeding trigger now at critical...

at critical plus... plus...'

Toba glanced across at his superior in alarm. Rago was staring in utter disbelief at the elevator cubicle which had just brought up the last of the Quarks.

'Toba...' Rago gasped in a hoa.r.s.e nightmarish croak, pointing at the floor of the cubicle. 'Toba... abandon..

At that moment, the saucer tipped slightly and something rolled out of the cubicle and trundled noisily across the deck towards the dais. It was the seeding trigger, now glowing a deep crimson.

The Dominators gaped speechlessly at the giant egg as it zig-zagged around the gently gyrating deck, glowing brighter and hotter every second...

The vast saucer had shrieked away into the Dulcian evening sky just as Jamie reached the TARDIS, after helping Teel and Kando to carry Kully to the capsule.

'Thank goodness you're safe!' cried Zoe, meeting him in the doorway. 'But there's no sign of the Doctor yet.'

'Och, I knew I should've gone with him...' Jamie panted, shaking his head ruefully.

All at once there was a mighty roaring noise and a jet of flame erupted out of the sand nearby. They flung themselves face-down and covered their heads. After a few seconds the roaring ceased and the ground stopped shaking. A thick column of smoke and sand hung over the TARDIS. Badly shaken, they scrambled up. In the distance they could see three similar pall of smoke rising high in the air.

'They've just fired the rockets at the perimeter boreholes...' yelled a familiar voice. The Doctor came stumbling over the dunes, dusty and out of breath. 'Quick, you two into the TARDIS!' he shouted.

'But where's that big egg thing?' Jamie asked.

'Later... later. Get inside...' the Doctor gasped as he reached them.

Jamie pushed Zoe into the dilapidated police box and followed her. 'Yon Dominators got away...' he muttered angrily.

Just as the Doctor was about to enter, a brilliant flash of incandescent white light burst over the darkening sky. He turned and paused in the doorway, a faint smile hovering over his grimy face. A few seconds later, there was a sharp crack which rumbled and echoed and re-echoed overhead for quite some time.

The Doctor winced. 'I think I prefer them poached myself...' he chuckled.

Suddenly the ground started to tremble and the surrounding dunes began to undulate like waves on the sea, causing the TARDIS's ancient woodwork to protest vociferously.

'Doctor... come on... the whole planet's going to blow up!' Jamie yelled from inside.

The Doctor smiled with benign satisfaction. 'No, no, Jamie, the planet is quite safe now,' he called. 'This is only a local earthquake caused by the rockets. It'll only affect the Island, you know.'

There was a moment's delay then Jamie appeared in the doorway next to him. 'Aye, maybe, Doctor. But we happen to be on the island.'

At that moment, there was a terrifying tearing sound and a huge split started to open up in the dunes, belching orange sparks and sticky red lava and hissing clouds of gas and steam.

The Doctor's eyes widened as he watched the boiling, bubbling fissure rushing hungrily towards them.

'Oh dear,' he mumbled, rubbing the end of his nose with a crooked finger. 'Oh my goodness me... out of the frying pan and into the fire...'