into the control rod emergency drop mechanism, jamming the boron steel rods in the raised position, where they could not halt the rising temperatures in the core.
Others severed the pipework leading from the neutron absorber tanks. The gadolinium solution spilled away into the containment drains, removing the last line of defence against an uncontrollable runaway reaction that would destroy the reactor and the mine.
It would not be a nuclear explosion; no fission reactor contained enough material to do that, but it did not need to be. The reinforced core would rupture and explode with sufficient force to level the entire surface facilities and devastate the upper workings, and flood the entire mine with deadly radionuclides.
And then there were the intruders.
Two of them were dead already; Bob Five had seen to that, but four more remained at large. The robots’ slow brains dealt with this issue logically, just as they had before; the survivors would be hunted down and killed; it was just a matter of time.
CHAPTER THIRTY-SEVEN
Matt and Bergman ran along the haulage way, away from the robot, and back towards the deeper parts of the mine.
‘Which way?’ Bergman panted, as the fork leading to the sub-main shaft station came into view.
‘Go right,’ Matt said, ‘into the workings.’
They veered off, away from the shaft station, and through the pressure doors that they had seen on their first exploration.
Bergman stopped on the other side, and hit the manual door close button. The twin halves of the door slid shut, and closed with a clunk.
‘Can the robot operate the controls?’ Bergman asked anxiously, looking at the doors. He could hear the steady thump of the approaching robot on the other side.
‘Yeah, it can. Hold on.’ Matt opened an access panel on the door control box, found the isolation switch, and turned it to the locked position.
‘That should slow it down a bit – it’ll have to break through the door to follow us,’ Matt said with satisfaction.
They set off again at a run, trying to put as much distance between themselves and the robot as they could.
Suddenly, from the comlink in Bergman’s pocket, came an anguished cry:
‘Crawford, Bergman – please respond. Abrams, Elliott, if you can hear me, respond. If anyone can hear this message, please respond!’
Bergman tried to answer his comlink while he ran, but it slipped from his fingers and fell into the dust on the floor. He swore, and stopped to go back for it.
Behind them, on the other side of the locked pressure door, the robot heard the transmission as well. It swivelled its head to one side of the passage, and lumbered over to a cable bundle. Raising one of its arms, it slid a pincered hand round the cables, and sliced them cleanly in two. There was a loud bang and a bright flash as it cut off power and communications to the rest of the passage.
Bergman got to the comlink, just as the lights went out.
‘Fuck!’ he yelled, scrabbling to pick it up in the darkness. He opened the handset and read the illuminated display.
‘There’s no signal. The bastard robot’s cut the links.’
‘But they’re alive!’ Matt said, clicking his flashlight on. ‘Clare and Steve are still alive in the silo. If we can reach them, we can still escape.’
Bergman looked back at Matt, his face a mixture of hope and fear.
‘How are we going to get back to the silo? We can’t go back to the shaft, the robot’s behind us.’
‘We can get there by going up the return shaft.’ Matt spoke urgently. ‘There’s an air bypass duct that goes between the top of the shaft and the main return airway. It’s there to balance the air flow. It’ll take us directly to the silo.’ He stared at Bergman, willing him to believe in the chance.
‘Are you sure? I can’t remember the layout of the workings well enough.’
‘Trust me, it’s there. Come on, we’ve got to reach them before they lift off. They don’t know we’re still alive!’
Bergman switched his flashlight on, and set off after Matt. They ran on into the passage, their flashlight beams skittering over the walls.
It was utterly dark in the haulage way; not even the emergency lights were working. Behind them, a loud
The air grew chill; they were heading towards the ice workings. After a few hundred metres, Matt turned aside, down another wide passage.
‘Cross cut,’ Matt said. ‘Connects with the return airway.’ He halted by another open pressure door, about twenty metres in.
‘These should
They stepped through, and Matt closed the door behind them, and locked it with the isolation switch. In the distance, the rhythmic pounding had stopped, which could only mean that the robot had broken through the doors, and was moving after them once more.
‘Second set up ahead.’ Matt pointed up the crosscut. Twenty metres further on, another set of open pressure doors formed an airlock, to allow men and materials to move between the intake and return airways without disrupting the mine ventilation.
They closed and locked the doors behind them. There were now two sets of locked pressure doors between them and the robot, and they felt slightly safer.
‘Come on, we’re nearly there.’ Matt led off down the crosscut, and a light grew ahead; they were approaching the return airway.
They clicked off their flashlights as they came to the end of the dark crosscut, and peered out cautiously into the brightly-lit passage. The return airway was quite different from the passages on the other side of the mine; this was the route through which the output of the ice mine came, on its way to the skip loaders that would hoist it up the return shaft to the refinery.
The passage was dominated by the support framework of the belt conveyor, which occupied over half the width of the passage. When the mine was working, the conveyor would have run constantly, transporting ice from the underground workings to the waiting skip loaders. The mud from the melting ice had dried to strange, circular patterns in the floor, and the walls were grey with dried mud and spray.
They looked carefully both ways before leaving the crosscut, and turned right, heading for the return shaft.
Inside the silo, Clare sat in the shuttlecraft, staring ahead. Her tears had dried on her face, and she knew she had failed. Her mission had been simple; to convey her passengers to Mercury, and return them home safely.
Now, every one of the passengers was dead, and she had to return to the shame and the investigation boards. It would have been better if she had died along with them.
Wilson sat next to her in the copilot’s seat, checking the flight plan as they waited for the launch window to open. They could not delay any longer; outside the silo complex, the security cameras showed two robots attacking the pile of rubble that blocked the airway. Every few minutes, a distant rumble reverberated through the silo as another large boulder was moved aside. Soon they would be through, and then it would be the end.
Clare almost wished they would break through, and that the air would rush out, so that she could die in her misery. It would be so much easier than going back.
She looked at her comlink for the hundredth time, to see if there were any messages. There were none, and
