Plot

Several strangers converge on a hotel in Venice, Italy, where a bellboy's bad English sets them up to clash against each other in a hilarious case of mistaken identity.

Mike Lawton (Bryan Brown) (a hitman), Maurice Horton (Richard Griffiths) (expecting some middle-aged dating agency nooky), and Melvyn Orton (Dudley Moore) (checking out properties for his boss) converge on the Hotel Gabrielli in Venice, Italy. Linguistic mix-ups by the staff mean each of the trio get wrong instructions for the next day. So Maurice meets up with puzzled estate agent Caroline Wright (Patsy Kensit) to see what she's offering, Melvyn attempts to make a gang of hoods an offer they can't refuse on their villa, while Mike sets off to rub out a lonely-hearts lady from Huddersfield.—Jeremy Perkins {J-26}

Mike Lawton (Bryan Brown), Maurice Horton (Richard Griffiths), and Melvin Orton (Dudley Moore) are three men who come to Venice. One of them is a hitman sent to take out a mobster. Another is a lecher looking for a little action with a woman he never met, with whom he was set up. And one of them was sent by his employer to inspect a property his boss wants to buy. All three men stay at the same hotel. But when the Bellboy (Bronson Pinchot) gets their names mixed up and gives information meant for someone else. So one of them meets realtor Caroline Wright (Patsy Kensit), who will do whatever she has to, to close the sale. And another follows a woman looking for romance. And another goes to the home of the mobster who thinks he's sent there to kill him.—rcs0411@yahoo.com

Three middle-aged men board the same plane at Heathrow Airport in London bound for Venice, Italy. They are: Melvyn Orton (Dudley Moore), a shy and unassuming clerk with an assignment of purchasing a house in Venice under penalty of losing his job; Mike Lawton (Bryan Brown), an Australian-accented hit-man en route to Venice to kill his next mark, and Lord Maurice Horton (Richard Griffiths), a rather obese man who is mayor of a small city in rural England.

All three men register in the Hotel Gabrielli. The first to check in is Maurice. He establishes that his name is Horton with an overeager bellboy (Bronson Pinchot) who (due to his poor knowledge of the English language) struggles with properly pronouncing the letter "H". Melvyn arrives next. He is checked in by the hotel's manager, who initially believes that he and Mr. Horton are the same person until Melvyn clarifies the spelling of his name. Third to arrive is Mike Lawton. They are all expecting messages: Melvyn from an estate agency that is selling a worthless villa in the Lido, Mike from the Mafia, and Maurice from a dating agency called Medi-Date.

That evening, when the bellboy receives the message for Melvyn, he mistakenly delivers it to Maurice. The message from Medi-Date goes instead to Mike, who now believes that his "mark" is the woman Maurice was supposed to meet with. Melvyn, meanwhile, receives Mike's instructions to 'visit' a local mob boss.

The next day, Maurice is shown around the villa by Caroline Wright (Patsy Kensit), the Estate Agent who has received instructions to sell the house immediately. If she gets the money in cash, her commission will be tripled, allowing her to purchase a speed boat. Maurice is under the false impression that they are on a date, planning to have sex with her, but is baffled by the fact that she seems very intent (supported by double entente) to get to "the nitty gritty."

Mike is following Patricia Fulford (Penelope Wilton) (who was supposed to be Maurice's date) around Venice, trying to find the courage to kill her, since he is having second thoughts about his chosen profession.

Melvyn goes to a house and calls upon seeking Mr. Scarpa (Andreas Katsulas), a mafioso boss who knows he is being sought by a killer, and is detained by thugs, taken to a cellar and tortured when they mistake Melvyn as the hit-man.

As Maurice takes Caroline out for lunch, Patricia has noticed Mike following her around and engages him in conversation. Mike is unsure of what to make of this, since he believes he is there to kill Patricia and she believes he is trying to go on a date with her.

Melvyn is permitted to call his boss Mr. Marshall in England, trying to prove his story that he is there to buy Mr. Scarpa's extravagant house rather than kill him. While Scarpa and his men listen, Marshall (voice of Lindsey Anderson) thunders abuse at Melvyn and hangs up. Scarpa remarks that Melvyn is living life like a worm, letting his boss insult him so freely, but is still convinced he and this "Mr. Marshall" want Scarpa dead. The interrogation resumes, with Scarpa's men preparing to use electricity on Melvyn's genitals, but he remembers a man at his hotel (Maurice) with a similar last name. Scarpa and his men, now suspecting Maurice as the assassin, head to the hotel and take Melvyn with them.

Meanwhile, Maurice has tried to make a move on Caroline, who is offended, both still mistaking other's agenda. His belief that she is a prostitute is compounded by her confusion that he would pay cash for the villa if she agrees to have sex with him.

Mike is about to kill Patricia but stops at the last minute. Everyone returns to the hotel: Maurice and Caroline to have sex, Mike to figure out what to do with Patricia, and Melvyn to check out and run for his life.

Melvyn is trapped again by the mafiosi and led upstairs to a new room. Mike and Patricia have clarified that she is not his mark and that Medi-Date is a legitimate company, not a cover. Maurice, after having sex with Caroline, informs her he isn't going to buy the villa, since he lives in England and has little use for a home in Venice. Melvyn is being tortured again when the bellboy comes in, escorting Mrs. Rosemary Horton (Alison Steadman), who is irritated to discover she's been led to the wrong room.

Caroline is in Maurice's bathroom, considering the possibility that Maurice may very well cheat her out of the money he'd promised when the bellboy brings Mrs. Horton in to the correct hotel room. She has become suspicious that Maurice is cheating on her, and after speaking with his secretary became certain Maurice was going to Venice to meet another woman. Caroline uses this as a chance to blackmail Maurice, implying that if he pays £100,000... in cash, she will keep their tryst secret.

Maurice calls his bank manager in the UK to have the money transferred to him in Venice, a conversation overheard by both Mike and the mafiosi. Mike and Patricia mistakenly assume that Maurice has killed the mark and received the money, since one hundred thousand pounds was Mike's fee. The mafiosi have decided to kill Mr. Horton and Mr. Orton, convinced the former is a cleverly disguised assassin and that the latter knows too much. They obtain a remotely detonated bomb, intending to make use of it later.

The next morning, Maurice receives the money, places it in a briefcase, and leaves it in the hotel safe. The mafiosi get a matching briefcase in which they hide the bomb, and force Melvyn to also place it in the hotel safe (after having to spell his last name out 'Orton' for the incompetent bellboy who continues to confuse the names between the three men). Then, after setting a small fire to lure the bellboy away from the front desk, one of Mr. Scarpa's goons, Rossi, swap the tags on the two identical briefcases.

Maurice takes his briefcase and leaves for the villa with Mike and the mafiosi in pursuit. Mike and Patricia then ambush the Hortons and try to steal the suitcase and a struggle ensues between them, the Hortons, and Caroline over the money. Melvyn, sitting in a rubber raft offshore, is ordered to set off the bomb by an impatient Mr. Scarpa, whose speedboat is sitting further offshore, unable to get any closer. As Melvyn tries to comply, one of Scarpa's henchmen, Alfio, realizes a horrifying mistake: he and Rossi both swapped the tags on the briefcases during the switch back at the hotel. Realizing (way too late) that the bomb is on the boat, Scarpa screams at Alfio and Rossi to throw the briefcase overboard and begins firing at Melvyn with a silenced pistol. Scarpa is trying to stop him from setting off the bomb, but Melvyn assumes the Mafiosi have become impatient and are telling him to hurry up. The detonator finally works, and Scarpa's boat explodes and sinks killing Scarpa and both of his henchmen aboard.

After the Hortons and Caroline clear the air over the money, Mike retreats to the Hotel Gabrielli in a panic. Mike tells Patricia that the nameless criminal organization he works for doesn't forgive mistakes (not even just one), and given what has happened he now fears for his life. When the bellboy knocks on the door (having gotten his room number and name correctly), Mike grabs him and holds him at gunpoint while Patricia reads the message from Mike's employer: since his mark (actually Mr. Scarpa) and two of his top men were killed, he has been paid a generous bonus in addition to his original £100,000 fee in his Swiss bank account.

Melvyn, wearing soaking wet clothing after swimming ashore and evading the police, arrives back at the hotel where the bellboy (now finally aware of his Melvyn's last name) reads for him a profanity-laden message from his boss informing Melvyn that he is fired from his job. Safely back in his own hotel room, Melvyn calls Mr. Marshall and tricks him out of £355,000, the price for Mr. Scarpa's house in Venice.

Melvyn takes the money and leaves the country for the Bahamas, where he sets up a sporting goods business specializing in testicle protectors.

Mr. Marshall arrives at Scarpa's house sometime later (off-camera), and Mr. Scarpa's men avenge their boss by killing him.

Caroline finally gets the speedboat she has long dreamed of owning, but it crashes due to faulty engineering and she cheerfully sues the boat's maker for all the money she can get. She later marries a sumo wrestler.

The Hortons' Venice villa falls apart and so does their marriage. The former Mrs. Horton soon finds a new and better husband, while Maurice is still looking for love when the film ends.

Mike and Patricia, having become very fond of each other in their time in Venice, decide to marry. Mike finally ends his career as an assassin. Mike, under his real name of Charlton Black, opens up a flower shop in London as he had long desired to do. Patricia goes on to represent England in the Olympics, having become exceptionally skilled with short-barrel firearms.

Also in a final on-screen text, the nameless and incompetent bellboy was later fired after a few too many complaints from hotel guests and took another job at the Hawaii Hilton, which lasted for only a "whole half-hour".