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.

The mountain completed each rotation in less than seven lapses; her motion was stretching that out threefold, but rather than hanging back to witness a full turn at every radius she had to trust her companions to cover their own portions of the territory. Agata wished she could have made it a mathematical certainty that no square scant would go unsearched, but before she’d been out here and seen the conditions she’d been in no position to make binding plans. All she could do now was hope that most of the team found their own workable strategies, and between the symmetry of their initial placement and the shared conditions that prompted their individual actions they’d end up executing a combined sweep without too many gaps.

She began moving steadily in towards the axis.

The change below her was so stark and it came so abruptly that Agata almost began chasing it, but she caught herself in time. The smooth black expanse of the engine’s rebounders was unmistakable, and the visual jolt of entering it was followed by near-perfect homogeneity. The idea of the occulters drilling into this precious lode was shocking – and it would also be the place where their camouflage was the least effective – but Agata decided not to speed past the region. However strong the argument for the machines avoiding it, she couldn’t trust her adversaries not to exploit that presumption.