After blowing the whistle on a colleague Detective Grace Narayan is sent to a small Welsh island; there she encounters local GP Doctor Pridaux who explains that his son Cai vanished a year ago, but the investigation proved fruitless.

An identification is made of the body and Grace is keen to prove it was murder, but a murder investigation team arrive from the mainland and take over proceedings.

A huge storm hits the island, forcing Grace to spend time with all the locals under the same roof. Grace continues to investigate Cai's death. Silas provides an interesting lead, The True Way.