The Arrows of Time

When the shutter closed there was nothing to feel, and in the perfect darkness no way to be sure that it had happened. But then the exiting wind rustled the fabric on her limbs and starlight entered the tunnel from below. Agata didn’t look down for confirmation; she just brought her limbs together and let herself fall.

Half a dozen strides from the outlet she drew a circle on her chest and the jetpack eased her to a halt, supporting her as she followed the rotation of the Peerless. She sketched an upwards arrow and ascended, until a safety handle set into the rock for maintenance workers came within reach. Wide-field cameras on the slopes monitored the space around the mountain, with their feeds analysed automatically to detect anyone in trouble falling away into the void, but as long as the team remained close to the hull they’d be out of view.

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.

Agata turned herself around so she was facing the surface at an angle where she caught the reflection of the stars. The grey blur shimmered with colour now, the texture visible if still mysterious. She sketched a double arrow to begin reducing her relative motion; the jetpack complied, though it sent a warning message through her corset, alerting her to the cost.

She waited anxiously, afraid that this unrehearsed strategy would get her nowhere, but then the transition came in an instant: suddenly, the shimmer from the rock was comprehensible. Agata could see the small bumps and concavities, the fine crevices, an endless parade of details rushing by beneath her. The occulters had been clad well enough to blend in with the stone around them from a distance, but she was only a couple of strides from the surface. If she kept her concentration, the machines ought to be unmissable.