Margo and Neil DeWitt sees like any other fun-loving, super-rich couple until Chicago Police Commander Larry Cole sees through their affluent charade. While investigating the death of a fellow officer, Cole stumbles across a pattern of killings that leads him to discover the DeWitt's gruesome hobby: murdering women and children using methods from their favorite mystery novels. Cole enlists and group of mystery writers to help him figure out where the homicidal couple will strike next. But as the body count rises, will it be enough of an edge to help him get to the DeWitts before they get to him?