A bored Hercule Poirot announces that he is going to retire and suggests that he and Captain Hastings go to the seaside for a short holiday. While there, they meet a pleasant young woman who is delivering a set of miniature portraits to an American buyer on behalf of her aunt, an antiques dealer. When they arrive at their destination she is shocked to find that the miniatures are missing and that the American had already bought them from an elderly lady more than an hour before. As Poirot has retired he leaves the case in the hands of Hastings who slowly puts the facts together and not surprisingly comes to the wrong conclusion. In the end, it is left to Poirot to suggest the solution to the crime and brings all of the parties together for an interesting lunch.