The maverick and highly skilled killer Jack (George Clooney) came to an idyllic town in the Italian countryside, intending to retire after completing this mission - assembling a special rifle for the female killer. In this relatively simple and peaceful environment, Jack, who was originally low-key and cautious, unexpectedly established a deep friendship with the local residents. Not only that, he also met the beautiful prostitute Clara (Violante Placido), and a romantic love began. However, the last mission in this killer's career was far from simple as imagined. This film is adapted from Martin Booth's novel "A Very Low-Key Gentleman".