Luckily, Murder Mystery has a little more going for it than references to '70s rock songs. The script, which was penned by Zodiac and White House Down screenwriter James Vanderbilt, has a slightly more appealing high-concept set-up and a more intricate plot than many of the shaggy, poorly put-together Happy Madison productions. Married for 15 years, Nick and Audrey are presented as a fundamentally loving but economically pinched couple that struggles to find time for themselves. (Nick's idea of a thoughtful anniversary present is an Amazon gift card.) At the opening, Nick finds out he's once again failed the detective's exam -- he says he knows all the answers but he just freezes up under pressure -- and he lies about his test results to his wife, which snowballs into another lie that leads to him springing for a cheap European bus tour, a long-delayed honeymoon vacation promise.
But once the rakish Cavendish appears, all their plans change. The suave mystery man brings the Spitzes on his family's boat, where we're introduced to a series of Clue-like caricatures, including a famous actress (Gemma Arterton), an eye-patch-wearing Colonel (John Kani), a beard-sporting bodyguard (Ólafur Darri Ólafsson), and a non-English-speaking Formula One driver (Luis Gerardo Mendez). Everyone has assembled for a celebration of Cavendish's billionaire uncle Malcolm Quince (Terrance Stamp), who will soon be marrying Cavendish's former fiancée, Suzi (Shioli Kutsuna). It sounds unwieldy, but all the introductions and story mechanics are handled in a refreshingly sprite manner, with Aniston and Sandler often commenting on the absurdity of the scenario.
Inevitably, a murder on the high seas occurs: Quince tells off his friends and family, pledging to leave them nothing in his will and instead giving away his funds to Suzi, but before he can sign the contract that solidifies this arrangement, the lights flip off, a gunshot rings out, and the billionaire is found with a giant knife in his chest. From there, Sandler's Nick reluctantly attempts to take control of the situation and Aniston's Audrey, excited by the prospect of solving a real-life whodunit, begins theorizing about who the culprit might be. Could it be Quince's son Tobias (David Walliams) who might want all the inheritance for himself? Perhaps Cavendish did it? Or maybe the Spitzes aren't as innocent as they look?