Elliott has never thought of himself as a hero. Until one dark night he meets Rebecca, a scared and vulnerable young woman who needs his help. There's a man harassing her, following her; would he mind pretending to be her boyfriend, just while she walks home, to put him off? And that is that - just a favour for a stranger - until there is a knock at Elliott's door. It's the man who was following Rebecca. He claims he's her ex-boyfriend, but it's clear that he's been stalking her. He's obsessed, dangerously so. He wants Rebecca, and he will do anything to have her. When Elliott eventually tries to tell him the truth, the man doesn't believe him. The only way to save himself is to get Rebecca to explain. There's just one problem: Rebecca is nowhere to be found. And now it looks like one good deed will cost Elliott everything...