Joan was curled in Smith’s arms. ‘What… what was that?’ she cried.

‘Some sort of explosive,’ Alexander called from the hedge, trying to shout over the ringing in his ears. The boys were all shouting and openly sobbing, finally giving in to the fear that had pursued them for so long.

‘A fusion bomb.’ Benny spat to get the dust out of her mouth. ‘High blast, very low radiation yield.’ She stood up, and shivered at the spectre of the mushroom cloud that was rising above the slight valley that had once contained the school. ‘I had hoped that I would never get to see one of those.’

Smith got slowly to his feet, pulling Joan up with him. The first people were staggering, shouting and screaming, out from the still-intact pub.

‘All those boys…’ Joan whispered. ‘And the teachers…’

Smith held her tight, marvelling at the terrifying shape in the sky.

Tim had been wandering in the forest, wondering when the time would feel right to do anything. He’d felt suddenly certain when he’d happened upon the barrier and rescued that soldier. That had been like following lines in a play, remembering his cues. Now, he was back in the wings, waiting to be called again, hearing the faint whispers that seemed to come from the Pod in his hand.

He’d been startled by a noise in the bushes and come upon Wolsey, staring up at him from his hiding-place in annoyance.

‘Hey, come on, boy, come on.’ Tim dropped to his knees and crawled towards the cat, clicking his tongue. Wolsey decided that the smell of the boy was interesting and strange, and not really frightening, and so edged up to him, rubbing his neck against Tim’s hand. ‘That’s a good cat. Now where⁠ —’

That was what saved Tim from the explosion. Suddenly, all the trees on the hill were flat, and he was lying under one of them, the weight of its fall broken by the shrubs that Wolsey had been playing in.

As the roar rumbled away, the cat leapt off, jumping from tree trunk to tree trunk very fast.

Timothy clambered out from under his particular tree, holding his ears. He counted the descending note of the sound, wondering what he was doing as he did it, and came to some startling conclusions about distance and explosive force.

‘The school!’ he whispered to himself. ‘What have they done?’

The family opened their eyes, blood still on their lips. They were standing in a small force dome, in the centre of the school. Beneath their feet was a circle of unharmed tiling.

Above their heads stood the school.

Only now it was made of fused glass. Patterns of light from the shimmering cloud scattered through it, rain bowing the gym and the library and the kitchens. Multiple lenses twisted the images and magnified them, the fiery brightness flickering through the Upper School and along the dormitories.