Sophie Malaterre, a 25-year old fashion illustrator living in Montreal, has steeled herself for a lonely summer in the city. She has no plans, no close friends around and no boyfriend. In desperate need of a change of scenery she hears about an apartment-swapping site: switch.com. As luck would have it, she finds an apartment in Paris, complete with a view of the Eiffel Tower. Paris is everything she has ever dreamed of and her first day there is idyllic. But the next morning she meets with a rude awakening as the police burst through the apartment door. Sophie discovers she has been sharing her apartment with a headless corpse. Caught in the chaos Sophie has no way of proving that she is not the owner of the premises, a woman she has never met called Bénédicte. Sophie's fingerprints are on the murder weapon, Bénédicte's passport has Sophie's photo in it. Nothing adds up. As the walls close in Sophie realizes she hasn't just switched flats... She's somehow switched identities...