In London to celebrate his birthday with James (Peter Gallagher), his rich younger brother, hapless American Wallace Ritchie (Bill Murray) gets signed up to participate in an elaborate role-playing theater performance. However, when Wallace accidentally receives a call intended for an actual hit man, he gets caught in a web of intrigue, completely unaware that the action unfolding around him is real. Luckily, the lovely Lori (Joanne Whalley) is around to help the clueless guy out of tight spots.