Frank (2006)

Desperation drags a man to start working for an assassin in this thriller. Rob is an all-American guy, but he loses his naiveté when he journeys to London to find his girlfriend. Just before she dumps him, he learns that she has been earning money in the British city by stripping. With empty pockets and a broken heart, Rob does the only thing he can: become an assistant to a hitman named Frank.