‘Shine your torch around.’

Cynthia opened her eyes to see the yellowing light reflected from a ceiling only a few feet above her. They were in a kind of alcove that lay alongside the river. It measured about twelve feet square, and the ceiling ran down at an angle to meet the floor.

Albrecht said: ‘The torch is nearly done.’

‘If the river rises suddenly,’ Henry said, ‘we’ll be drowned like rats.’

The light clicked off. ‘If we try to go on without first sleeping, I think we will drown anyway. But it does not matter. If we rest for half an hour, then we shall sleep. I think Cynthia sleeps already.’

Whatever they decided, they would not make her move from here. No bed had ever been as welcoming as this bare rock. Sleep was so near that it was a luxury to hold it off for a moment. Only a moment.

‘All right,’ Henry said. ‘We stay. We’d better huddle up as close as possible – being on top of the river will keep us cooler than we were last night.’

The two men settled themselves on either side of her. Their bodies, beside hers, were warm and reassuring. Everything was all right, after all; even the sharp pain of hunger was dulled by her tiredness.