Nick and Audrey Spitz are a married couple who have been struggling financially and professionally. One day, they are invited to a luxurious yacht by their wealthy friend, Charles Cavendish, to celebrate his marriage to his fiancee, Suzi. During the celebration, a mysterious and glamorous woman offers Audrey a ride on a seaplane, which she accepts. When Audrey returns to the yacht, she discovers that Charles has been murdered and a con man has taken his place.
Nick and Audrey are then mistaken for the killers by the Interpol agent, Inspector Laurent Delacroix, who is investigating the case. Now, they must clear their names and find the real killer or killers, all while being pursued by the police and various criminals who want to kill them. Along the way, they encounter a series of eccentric characters, including Charles' greedy family members, a Russian oligarch, and a Maharaja.
Throughout their investigation, Nick and Audrey try to stay one step ahead of everyone else, constantly coming up with alternate theories and suspects. They eventually discover that the kidnapping was all an elaborate scheme to cover up a massive art heist. With the help of Delacroix, they are able to apprehend the real culprits, and clear their names.
In the end, the Spitzes' detective agency becomes a success and they are hailed as heroes. However, they are still not sure if they can trust each other, as they both kept secrets from one another during the investigation.