A Venice hotel finds itself occupied by three men with similar-sounding names: purchasing agent Melvyn Orton (Moore), professional assassin Mike Lorton (Brown), and minor British politician Lord Maurice Horton (Griffiths). Each of the three is there for an appointment of a very different nature.
Due to the bellboy (Bronson Pinchot) getting their names mixed up and delivering messages to the wrong men, Melvyn goes to the home of a dangerous mob boss (who's on the lookout for a foreign assassin) while believing that he's supposed to buy it; Mike starts following a woman who signed up for a blind date due to getting her picture and name in an envelope; and Maurice ends up going out to lunch with real estate agent Caroline Wright (Patsy Kensit), who is desperate to make a sale, while thinking it's a blind date.
This film contains the following tropes:
- The Alleged House: The Villa Romano, which Caroline is trying to sell and Melvyn was sent to purchase, is not a prime piece of real estate.
- Dramatic Irony: None of the three men ever learn of the existence of both of the others. Melvyn becomes convinced that Maurice is the hitman who was supposed to be sent after the mob boss (something he manages to convince his captors, who come to agree with this belief), while Mike thinks that Maurice was the one who got his envelope to carry out the assassination.
- Exact Eavesdropping: Played for Laughs when Mike and Patricia overhear Maurice having a lot of money brought in (to buy the Villa Romano) and mentioning Caroline Wright. They believe that Caroline was the person Mike was supposed to kill, and that Maurice decided to kill her and collect the money for doing so.
- Groin Attack: The main form of torture Melvyn suffers at the hands of the mafia. The end of the film mentions he started a store selling testicle protectors.
- He Knows Too Much: Even after being convinced that Melvyn isn't a hitman, the mafia believe this of him and plan to kill him.
- Hitman with a Heart: Mike wants to retire to become a florist, and can't bring himself to kill Patricia even before realizing she isn't his target.
- The Mafia: They serve as the main villains and pose a bit of personal danger to Mike and Maurice due to believing that the two are assassins.
- Mean Boss: Melvyn's employer is so awful that the mobsters flat out say they'd kill anyone who treated them like that after listening in on a phone call.
- Oh, Crap!: The Mafia goons get this when they realize that they both switched the bag that they're carrying with one rigged with a bomb, which Melvyn is just pressing the remote to blow up the bomb.
- Unfortunate Item Swap: three envelopes intended for three guests at a hotel get mixed up by the aforementioned bellboy (played by Bronson Pinchot). Later on the two suitcases with the money and the bomb, although that swap is only unfortunate for the bad guys.
- "Where Are They Now?" Epilogue: The film ends with one: Mike and Patricia are married. Melvyn is sell gin testicle protectors in the bahamas. Maurice and his wife got divorced.
- You Have Failed Me: Mike is very frightened about experiencing this form his bosses, but it doesn't come to pass.