Once, a long time ago when she was still a student, the Inspector travelled to the island of Santorini and scuba-dived among the ruins on the shallow floor of the Med. The sea was utterly clear, and she found herself unable to remember that it was composed of water. Her mind insisted that she was flying rather than swimming, that she was leaping weightlessly and impossibly between the stones of fallen temples, that the particoloured fish must be birds or insects. In this fugue state she was darting back and forth, laughing into her regulator with a clear, clean joy, when she felt a kind of electric shrugging. Her ears popped and her whole body growled and buzzed as if touched by a high-voltage wire. She heard a noise that came from inside her, transmitted through water into her skeleton and lungs and sounding there, audible in her ears by their connection and proximity to the source. She was played upon, and overcome, floating to the surface to stare at the bright Greek sun and a perfect sky. The noise came again, a different note, and finally again one last time like a harmony, and then was gone.