When you think you're safe, When you think you're all alone, That's when he'll come for you... A silent killer stalks the city, targeting those home alone at night - killing without pity or remorse. As panic spreads, Detective Inspector Helen Grace leads the investigation, but is herself a hunted woman, her every step dogged by a ruthless killer bent on revenge. As she tracks the murderer, Grace begins to suspect there is a truly shocking home truth that connects these brutal crimes...