Twelve minutes left.
She looked back at her map. Further to the south-west was a smaller crater, in deep shadow, which suggested that it must be fairly deep. She asked the computer for more information, and a text field unrolled on top of the hologram.
Sylvester Crater, she read. 58 kilometres in diameter.
Depth: unknown.
She liked the look of it. It looked almost tailor-made to swallow the energy of a nuclear bomb, and all of a sudden she had to smile. Sylvester, how appropriate. A crater named for the father of industrial explosives, and it would see the biggest damn explosion the Moon had known for thousands of years. Grinning, she changed course a few degrees south-west, and Callisto tore over Hermit’s western rim.
Eleven minutes.
The crater wall fell away beneath her, rugged, pocked by lesser impacts, and gave way to a broad, flat valley. The other side of the valley had to be Sylvester’s outer wall. Nina leapt from the pilot’s seat and ran to the airlock, suddenly scared that Palmer might have misread the timecode, but when she peered through the pane she saw the mini-nuke sitting on the cabin floor, its counter just ticking down from the ten-minute mark.
The sight of the bomb made her suddenly queasy.
09.57
09.56
09.55
Time to throw in her hand; she’d pushed her luck as far as she could. There was enough distance now between the bomb and the base. She ran back to the cockpit and gave the command to extend the airlock.
The computer gave her an error report.
Incredulous, she stared at the console. Suddenly the lift symbol was blinking, fiery red. She tried again to extend the shaft, but without success.
Impossible. Just impossible!
She demanded a report.
Airlock not fully drawn up, it said. Please draw up lock before attempting to extend.
Her legs trembled wildly. Hastily she ordered the shaft to draw up, even though it was already drawn up – at least, it had seemed that way, but perhaps there was a centimetre or so still to go. But the display didn’t stop blinking.
Airlock cannot be drawn up.
Cannot be drawn up?
Nine minutes.
Less than nine.
‘Are you crazy?’ she shouted at the control system. ‘Draw up, extend! How the hell am I supposed to—’
She stopped. You had to be completely crazy yourself to try arguing with a computer. The airlock wouldn’t open, and that was that. Which meant that she couldn’t just spit the bomb out that way, and she couldn’t fetch it from the lock to throw it out of the rear hatch.
The rear hatch!
Her heart pounding, she raced to the stern, opened the bulkhead to the cargo hold, charged inside and looked around. There were a few grasshoppers here, hanging in their brackets and ready to roam. It had hardly been eighteen hours since they had been using them to tour the legendary Apollo landing site. She loosened the clips on one of them, stood it up on its telescopic legs and checked the fuel tank. Enough. All right then, back to the bridge, but as she drew level with the airlock she couldn’t resist glancing inside. She hesitated, then looked in at the infernal device, saw the timecode running down—
06.44
06.43
– she tore herself away. Dashed into the cockpit.
Looked out.
Sylvester’s crater wall, still a good way off but growing larger every moment. She had to make sure that the bomb would explode on the crater floor, deep inside. Otherwise she would be dead for sure. Her fingers leapt across the instrument panel like a virtuoso at the keyboard as she calculated the angle of approach she would need for a controlled crash, and the shuttle’s nose dipped – no, that was too much, less! – there, that was it. A steady descent.
And now, out of here. Helmet on.
Her hands were trembling. Why were her hands trembling, now of all times?
05.59
The helmet wouldn’t fit.
05.58
She had left it too late.
05.57
05.56
Now!
Cargo hold. Manual controls.
The loading hatch sank down, infuriatingly slowly, to reveal the stars and, far off, the Peary–Hermite range. Nina climbed up onto the grasshopper platform and kicked the thing up into the air, just a little. The hatch yawned wider. A hair’s breadth was all she needed. Without waiting for it to open entirely, she steered the hopper along the cargo hold and through the shuttle’s rear hatch as it tore down towards the ground.
It would be an illusion to think that she was safe now. The shuttle seemed to be standing still relative to her speed, which meant that she was still hurtling towards Sylvester at 1200 kilometres per hour on her tiny craft, just as fast as Callisto itself. Realistically, her chances were just about as bad as could be, though she still had five minutes to achieve the impossible, maybe four. Somewhere between 250 and 300 seconds, at any rate. All her hopes hung on having calculated the proper angle of impact for the shuttle. She swung her nozzles to the horizontal and opened the throttle for as much thrust as the little machine could muster.
The hopper bucked and tried to throw her off.
Then it rushed for all its engines were worth away from Callisto, bravely doing its best against the murderous acceleration, and losing height all the while. The shuttle dwindled away rapidly in front of Nina’s eyes. She swung the nozzles around a little further and went down to the ground, too close to the ground, as she established the next moment, since she was still going much too fast. She was in danger of being smashed to pieces, and she steered the hopper up again, wringing the last drop of thrust out of its jets, and saw Callisto speeding towards Sylvester’s sunlit slopes. The dusty lunar surface was not racing past quite so fast beneath her now, the hopper was battling against its own momentum and winning. It was slowing down, but would there be time to slow it to a safe landing speed?
And if she could? How much time did she still have?
Two minutes?
One?
A small crater rushed towards her, zipped by below and then was lost to sight. An ideal spot to take shelter. Somehow she had to make her way back to the crater, but she was still travelling at considerable speed. Over on the horizon, Callisto hung above the sweeping wall of mountains, a gleaming point, so close to the rim that for a moment she was afraid that she had miscalculated and the shuttle would smash into the crater wall, that the bomb would explode there on the slopes, and that nothing would protect her from the fury of the blast.
Then the shining dot disappeared inside Sylvester, and she gave a victory whoop, since she’d won this point at least in the deadly game. Still whooping, she steered the hopper down, fought against her own headlong hurtle, and gradually, little by little, the contraption seemed to be bleeding off the speed that the shuttle had given it, even if it was still going too fast to land. She could forget about that little crater by now, it was already much too far behind her, but something about the same size sped towards her, maybe a little smaller. The ring wall was two, perhaps three kilometres across but it was astonishingly high, so that all of a sudden she was afraid that the hopper wouldn’t make it over the peaks, would crash. Just before impact, she yanked the machine upwards, scraping over the rim, and then looked down. The crater wall cast a threatening shadow into the cauldron, a curve of blackness like a scythe. She slowed further, flew over the opposite wall, then she could see the plain again and Sylvester, its peaks terrifyingly near, unsoftened by atmospheric haze.