Agata waited for Serena to emerge, and for two more of their companions to join them. They couldn’t stay to watch the whole team exit; there were only four handles, and hovering would waste too much air. Agata gestured to the others and they set off for the base.

The starlit slopes turned beneath them, the pale brown calmstone sliding past ever faster as they moved further from the axis, making their straight-line trajectories seem like giddy spirals. Agata kept watch for sudden changes in the topography ahead; the jetpacks knew the basic shape and motion of the Peerless, but they carried neither detailed surface maps nor proximity sensors. No one had ever intended the wearers to skim the slopes at high speeds, so if she slammed into an unexpected rise she’d only have her failing eyesight to blame.

The jetpack overshot the rim of the base, and the rock below her fell away to be replaced by black emptiness then a sudden, shocking dawn. She could see the blazing lights of the half of the transition circle that the mountain had been blocking, just peeking above the distant horizon. Agata sketched a down-arrow and the jetpack brought her closer to the rock; the dawn ahead vanished, but she still had the other half of the circle behind her. The base was slightly convex, so, however low she dropped, the Peerless wouldn’t hide the entire transition circle, plunging her into complete darkness.

She looked around for the others; she could just make out Serena away to her left and another anti-saboteur to her right. The jetpacks had been programmed to take the volunteers to equally spaced points above the rim, but from here it was up to each of them to choose their path on a sweep in towards the axis.

The rock below her was a blur, moving past at more than a saunter every pause, but if she tried to match its velocity she’d be constantly using her jets to provide the necessary centripetal force – which would empty her air tank long before she got halfway to the axis. In all her training exercises with Tarquinia, in all the manoeuvres she’d performed around the Surveyor, she’d never faced anything like this.

The occulters could be waiting almost anywhere; in their final flight they could cover a lot of distance quickly. She couldn’t assume that they’d all crawled close to their targets. So she had to find a compromise: she had to slow the relative motion of the rock just enough so she’d be sure to notice one of the machines sweeping by, and then try to move closer to the axis as quickly as she could, lessening the drain on the jets.