Azelio reached the plants; he squatted protectively in front of them. Agata turned to face the hillside.

‘I forgot to use my stopwatch,’ she confessed.

Azelio hadn’t; he glanced down at his belt. ‘Still a bit more than two lapses.’

Agata groped pre-emptively for an antidote to disappointment. ‘If this doesn’t go off, I think we could probably smash enough rock for a test plot by hand.’

Azelio buzzed. ‘Not finely enough.’

‘I’m serious! We could start with a pick but then mill down the rock chips – like making flour from grain.’

‘If it does come to that, I’ll be reminding you that you volunteered. One lapse to go.’

Agata felt her gut clench painfully. Her body was bracing instinctively for danger, but silence would be far worse.

The hillside erupted with light. She flung an arm in front of her eyes, but with her rear gaze she saw her shadow stretched out behind her. The ground shook, and she hummed softly, remembering the blast that had taken Medoro. But this was its opposite: a force that might finally heal the mountain, as much as it could ever be healed.

A warm gust of air struck her skin, carrying dust but nothing harder or sharper. The light had died; Agata lowered her arm and waited for her eyes to adjust back to the starlight.

A great, loose mound of debris lay at the base of the hill. Azelio rose to his feet and put a hand on her shoulder; she realised that she was shivering.

‘It’s all right,’ he said.

‘Yes.’ At his touch Agata ached to feel more of his skin against her, but as an internal voice started weaving a story of the only fitting coda to this triumph, she shut off the absurd fantasy quickly, less afraid of any prospect of fission than of making a fool of herself with Azelio. ‘Let’s go see how it looks.’

They approached the blast site cautiously. In the planning meeting Tarquinia had raised the possibility of a delayed secondary collapse, but as they drew nearer that looked less likely: the new rock face was almost vertical, but they hadn’t created an unstable cave or overhang.

Azelio strode forward to inspect the mound. He knelt and picked up a handful of debris. ‘It looks fine enough,’ he announced warily. ‘There’s some coarser grit in there as well, but that shouldn’t matter.’ He turned to face Agata. ‘I think we’ve got a real chance.’

Hearing the hope in his voice, Agata felt the sense of fulfilment returning more strongly, but it was stripped now of any desire to follow her instincts to the end. She had all she needed: Azelio’s friendship, and the satisfaction of having played a part in this scheme. It was enough.