The surface became rough and grey again. Agata forced herself to readjust her expectations: her prey would show much less contrast now. The temptation to look around for her companions was growing, as much out of a longing for the support of their presence as any real fear for their safety. But with her front eyes fixed on the rock below, her rear gaze couldn’t reach beyond the blackness of the orthogonal cluster. She tried to assuage the pangs by rekindling her anger with Ramiro and Tarquinia; at least that made her feel stronger and more focused. But as the pits and cracks in the stone swept by, she thought of Azelio, who believed that all their efforts were in vain. If a meteor had always been on its way, this charade would not deflect it.

A shape with hints of regular borders passed below her and was gone. Agata raised a triangle on her chest, the preprogrammed symbol to send the jetpack in pursuit. She waited anxiously for the rock to slow, but when it halted there was nothing below her. She edged sideways, stride by stride, and then there it was fixed to the rock: an occulter with a small package dangling from it, held in place by nothing but hooks and strings.

Ramiro had given her no details, but she’d been expecting some far more robust form of attachment. She took the knife from her tool belt, grabbed hold of the package and cut the strings.

The bombs would be driven by timers alone; any kind of trigger based on location would be too unreliable to take out all twelve channels simultaneously, and navigation was the occulters’ job. Still, Agata kept the centrifugal weight on her cargo constant as she ascended from the rock, following a helix that kept the surface motionless beneath her. If everything she’d surmised was mistaken and some accelerometer was ready to cry foul, better not to take a piece of the mountain with her.

When she’d reached a decent altitude she let the jetpack kill her circular motion and spare itself the costly countervailing force. Nothing exploded. Agata was tempted, briefly, to try to prise open the stone box and take a look at the mechanism inside, but the risk of a booby trap seemed to outweigh any prospect of learning something useful.

She was still ascending slowly, in free fall now. She released her hold on the bomb, then instructed the jetpack to return her to the point where she’d left off. As she watched the package shrink into the darkness, a glorious ache of hope came to her unbidden. There were only a dozen bombs: the volunteers outnumbered them more than two-to-one. If even half the other searchers were as lucky as she’d been, the job would soon be done.