He stared down at the sparks escaping from his foot. ‘Maybe this won’t go off – but if it does I don’t want us both dying.’

‘Then stay where you are!’ Tarquinia insisted. ‘It’s the shock wave in air that kills bystanders; if anything happens, the dome and the void will protect me. Look, we don’t have time for a debate! I’m going to start the manoeuvre now. If you get into trouble, shout.’

Ramiro said, ‘All right.’

He adjusted his grip on the rope, taking the opportunity to rest one arm for a lapse. He didn’t think it would be wise to try to mess with the cooling bag to let him extrude a fresh pair of limbs, but if fatigue really did start to threaten his hold he could try tying his corset’s photonic cable in a loop around the rope.

As the gnats drew closer together, the centre of the rope dropped lower, nearer to the engines. Ramiro began climbing towards Tarquinia’s side, alarmed at how much harder it was to make progress with the rope at a steeper angle. Tarquinia poked her head out through the hatch, then reached down and began winding the rope in; Ramiro could see her straining to shift his weight, but she was doing much more than sparing him the effort of the climb. With the rope shortened the angle improved, and Tarquinia kept winding until it was nearly horizontal again.

Then she disappeared back into the cabin, and the gnats moved closer still.

Ramiro clung on, trying to ignore the revived throbbing of his foot. Everyone had imagined the rogue defending itself with antimatter, or elaborate software to deal with would-be intruders. But the measure that had actually defeated him might not even have been a deliberate strategy: in those last days at the Station, whoever had reprogrammed the navigation system might simply never have had an opportunity to restock the decommissioned gnat with cooling air. At this very moment, they might be fretting over the possibility that their weapon had overheated to the point where every photonic lattice had cracked and the rebounders’ mirrors had split into shards.

Tarquinia turned the gnat so that its flat belly faced the rogue’s. Ramiro scrambled to keep himself away from both the engines below and the approaching slab of hot rock. As Tarquinia eased the gnats’ bases together he found himself suspended half a dozen strides below the hatch through which he’d left the cabin. With the side of his body resting against the polished grey stone of the hull, he could feel the surface growing warmer as heat spread into it from the rogue. But before he could panic, he registered a quickening flow of air from the cooling channels. Tarquinia’s gnat was built to run at three times its current power; the extra burden would not overwhelm it.

‘How long to the impact?’ Ramiro asked.

‘A chime and a half,’ Tarquinia replied evenly. ‘I’m going to start applying force now; this might get rough, but don’t let it shake you.’