Erin Greer is a cynical, struggling young actress in Montreal who makes a living working as an undercover decoy for a private detective agency specializing in exposing unfaithful spouses. Her job is simple: seduce married men just far enough to let their suspicious wives catch them in the act. Her routine is upended when she is hired to target Max Gardner, a handsome businessman whose wealthy wife, Dina, suspects him of straying. After Max falls for the trap and is confronted, Erin unexpectedly finds herself falling in love with him, breaking the agency's cardinal rule. As the two begin a real romance, a shadowy figure begins stalking Erin and brutally murdering people in her inner circle. Trapped in a terrifying labyrinth of paranoia, Erin is forced to figure out if the killer is her obsessively jealous boss, a vengeful former target, or if Max's wife has orchestrated a lethal frame-up to protect her fortune.