When the body of university student Clare Mills is dragged from the river, Superintendent John Lambert and his partner, Bert Hook, are first on the scene. It's a particularly tragic case, even in the eyes of the two seasoned detectives, so when they report Clare's death to her mother, they expect hysterics. But the woman's reaction is as strange a one as they've ever encountered. Lambert and Hook immediately suspect the parents, but as they examine Clare's life, they find plenty of other suspects.