The wave started at one end and washed towards the other. And it returned and so on, and so on; she thought that it might never stop, though she saw it diminishing, and she swept her fingers through the water again, bringing new waves to life. Sybil rose at last from beside the tub and glimpsed herself in the mirror, one hand at her mouth, the other cupping the small, greenish-brown shell of a turtle.

‘My goodness,’ her mother had said. ‘Where did you get that?’