The deepest secrets drive the darkest currents.
Strange tides are acting upon Cass Bainbridge. Impelling her to leave London and the comfortable home she shares with her partner, to take up a lecturing job on the south coast.
But Brighton isn't the natural choice for a woman with a long-standing fear of the sea. And dealing with some of the students on her course - surly, difficult or just plain odd - against the backdrop of a series of attacks on campus, means Cass is soon finding elements of her new life distinctly disturbing.
Painful memories begin closing in on her; the spectre of a secret that finally tore apart her damaged childhood and changed her life for ever. And the sense she is being stalked - a series of strange phone calls, a malignant presence around her flat-build the whispering stream of disquiet into a wave that threatens to engulf her.