Sophie Malaterre is fed up, with no work, no friends and no boyfriends on the horizon. When an aquaintance tells her about the holiday house swapping website SWITCH.com, Sophie jumps at the chance to stay in an apartment in Paris. But soon after she arrives, she realises nothing is what it seems. After a murdered man is found in her bedroom, she escapes the police and goes on the run to prove her innocence. It's up to Detective Forgeat to find Sophie before she, too, turns up dead. But things don't go to plan and Forgeat finds himself getting in over his head and operating outside of the law in a bid to save Sophie and hunt down the real killer.