The comms link continued to flash obstinately, and Ty finally activated it. In one corner of his visor an image popped up, of three interconnected white domes nestling together in a shallow crater. Digging equipment and spare parts for the spider-mechs were stacked out in the open. He noticed with a shock that at least one of the domes had been partly deflated.

‘Nathan, you need to get back to the surface,’ he was informed. Like the rest of the Mjollnir’s crew, Cesar Androvitch had no idea of Ty’s true identity. ‘Nancy’s come over to help us get packed. We’re going back over to the frigate.’

‘But why? There’s still too much to—’

‘Nathan,’ another voice cut in; this time it was Nancy Schiller, the Mjollnir’s chief of security. ‘I’ll explain everything when you get up here. Don’t bring anything with you. Leave it all for the spiders. Just get here as fast as you can.’

She cut the connection, so that Ty hadn’t even had a chance to tell her what he had found.

He pulled himself back along the passageway until he reached Shaft A, a borehole nearly thirty metres wide that cut straight through the heart of the asteroid, at which central point it intersected with a second shaft – Shaft B – running at a right angle to it. The asteroid itself was a little over thirty-five kilometres across; thousands of passageways, all identical in width but varying in depth, radiated outwards from each of the shafts.

He tapped at a panel on the arm of his spacesuit and, in response, one of a dozen spider-mechs that had been floating motionless near the centre of the shaft now moved towards him, propelled by tiny puffs of gas. The approaching device consisted primarily of a series of grappling arms that extended from a central hub a metre in diameter.

Once it had reached Ty, the spider rotated, presenting two handholds to him. Ty grabbed on to them, taking care not to look down the length of the shaft towards the asteroid’s core as the machine carried him back towards the surface. Despite the minimal gravity, one such glance was sometimes all it took to send his suit’s bio-monitors into high alert.

Instead he looked up towards a slowly widening circle of stars no more than a few hundred metres away – the white dwarf around which the clade-world had been orbiting for the last few billion years standing out clearly amongst the rest.