A simple message on an answer machine. But one that makes Innes Haldanes blood run cold. Isabella Velasco is a name from a past that Innes has tried hard to forget. In 1977 both she and Isabella had spent a fateful year at the Unit, an experimental home for dysfunctional teenagers in Edinburgh. Now, after almost three decades, Isabella is trying to make contact. But before she can reach her, Innes learns that Isabella has committed suicide. And shock quickly turns to fear when she hears that another former patient has also recently killed himself. Has some dark event from 1977 come back to haunt them all?