NOTE: This spoiler was submitted by Alex

NYPD Officer Nick Spitz (Adam Sandler) has recently failed his detective exam, but doesn’t want to tell his hairdresser wife Audrey (Jennifer Aniston). After a dinner for their fifteenth anniversary, Audrey confronts Nick about how despite his promises after they got married they never went to Europe. Nick is an extreme cheapskate who never does anything nice for Audrey. Nick panics and says he was planning to surprise her, and the two head off to Europe. During the flight, Audrey meets Charles Cavendish (Luke Evans), and the two strike up a conversation. Charles’s fiance has recently left him and married his uncle. He’s attending their yacht party and invites the Spitz’s to join them. When Nick finds out, he doesn’t want to go, but Audrey convinces him the fancy yacht will be much nicer than their low budget plans.

On the yacht, they meet Charles’s ex-fiance Suzi Nakamura (Shioli Kutsuna), cousin Tobey Quince (David Walliams), and actress Grace Ballard (Gemma Arterton), and racecar driver Juan Carlos Rivera (Luis Gerardo Mendez), and Maharajah Vikram Govindan (Adeel Akhtar). Audrey is creeped out by Colonel Charles Ulenga (John Kani), Charles’s uncle’s old friend, and his bodyguard, Sergei Radjenko (Olafur Darri Olafsson). Charles’s uncle, Malcolm Quince (Terrence Stamp), arrives to thank everyone for celebrating his engagement. He notes they are all in his will, until now – he calls them all leeches who deserve nothing. He says he’s drafted a new will leaving everything to Suzi. Just before he signs the new will, the power goes out – a gunshot sounds, screams ring out – and when the lights return, Malcolm has been stabbed through the chest and is dead.

Audrey identifies Nick as a detective, and so everyone turns to him for guidance. He orders everyone back to their rooms until the yacht reaches land. Nick thinks the case is open and shut, Maclolm’s son Tobey, but Audrey says its too obvious – and a gunshot rings out. They find Tobey dead, gunshot wound to the head. The next morning, Inspector Laurent Delacroix (Dany Boon) arrives and questions everyone. Every guest says the strangest thing about the evening was the random Americans there. Delacroix tells the Spitzes he suspects them of being the killers.

Once the ship docks, the couple are determined to prove they aren’t the killers, and begin chatting up the various guests looking for clues. One suspect is Juan Carlos, whose father died because of Malcolm. Nick centers on Charles, but Audrey, who likes Charles, just thinks Nick is jealous of him. That night, they get a note inviting them to another room – where they find Sergei with a gun, who orders them to listen. He tells them that years ago, Quince stole the Colonel’s girlfriend – and that they had a child who died in childbirth. He says that the Colonel asked him how to kill Quince. When someone knocks on the door, the couple hides – and when they come out, Sergei has been murdered. They flee from the killer out a window, climbing across the hotel ledge, and end up hiding in Grace’s room where they discover she is sleeping with Vikram.

Nick and Audrey see Delacroix on TV calling them the prime suspects and that they are wanted – and that Nick lied about being a detective. The two get into a fight and Audrey realizes he lied about planning the trip in advance. Furious, she leaves with Charles. When Audrey discovers Japanese allergy medicine in the car, she realizes Charles is meeting with Suzi. She follows him and runs into Nick, and the two deduce that Charles and Suzi did it together. Someone begins shooting at them and they flee. They find Juan Carlos who takes them to Suzi – she holds them at gunpoint but is then shot with a poisoned dart by someone in a mask. Nick and Juan Carlos chase the assailant but he gets away.

Audrey and Nick head to Charles’s mansion to confront him, but find him poisoned to death. They panic but huddle up to figure it out. The remaining suspects and Dellacroix meet them at the mansion, where they deduce that Grace is Malcolm’s long-lost child who didn’t die as they were told. She convinced Tobey to kill Malcolm, then killed Tobey – she tried to kill Nick and Audrey once they became suspicious, and killed Charles because he loved Suzi and not her. Grace denies everything, but Audrey finds one final clue that proves it’s Grace, who pulls a gun and takes Audrey hostage, but Nick shoots Grace in the shoulder, and she’s arrested. Afterwards, Vikram points out that Grace was with him when Sergei was shot, and Nick and Audrey realize Juan Carlos is the other killer and has been faking his inability to speak English. He did it for revenge for his family. He takes Dellacroix hostage at gunpoint and steals a police car. The Spitzes take a ferrari and chase after, crashing Juan Carlos and rescuing the detective. Juan Carlos comes after them one more time and is hit by Nick and Audrey’s original tour bus.

Dellacroix thanks them tells Nick he’ll reach out to help make Nick detective. As a thank you, he gifts them a scenic train ride on the Orient Express.