Cosmo Topper, a mild-mannered banker, is haunted by the ghost of his deceased friend, Marion Kerby. Marion and her husband George were recently killed in a car accident. Unable to move on to the afterlife, Marion seeks Topper's help to resolve unfinished business on earth. Topper, who previously had a supernatural experience with the Kerbys, reluctantly agrees to assist her. As they travel to the French Riviera, Marion’s playful antics continuously land Topper in comedic and embarrassing situations. Meanwhile, Topper’s wife, Mrs. Clara Topper, grows increasingly suspicious of his odd behavior and decides to follow him.

Once they all convene at a luxurious hotel, the misunderstandings and humorous episodes escalate. Topper, under Marion’s ghostly influence, finds himself embroiled in several chaotic events that raise the eyebrows of the hotel's staff and guests. Despite the challenges, Topper begins to see significant changes in his outlook on life, becoming less rigid and more adventurous. Marion's presence serves as a catalyst for growth not only for Topper but also for his relationship with Clara. However, the complexity of their situation reaches a tipping point as they work toward solving Marion’s unresolved issues, leading to an emotional and transformative journey for all involved.