On the docks, Carlie and Henry DeWitt watch as a magnificent jewel-encrusted wedding coach is loaded into a shipping container and onto a freighter. Recently engaged, Carlie and Henry are to leave for the Bahamas, but Henry won't leave the ship until he's absolutely sure that the coach is safe. A fight between dock workers breaks out and an errant truck appears on the dock after the container has been loaded onto the ship. Checking the hold once more, Henry, Carlie and the ship's captain are startled to discover a small hole drilled in the side of the container - and the entire coach missing. Banacek gets the case and is surprised to hear that Carlie and the milquetoast DeWitt are to be married. Dewitt has ordered the ship impounded, but it can only stay in port for 36 hours. Banacek immediately begins investigating, checking up on the crew members. The coach was meant as a wedding present from a Middle Eastern shah to his new bride - Hollywood star Diana Maitland. Banacek has a very in-depth interview with Diana, who is enthralled with the prospect of being royalty. Banacek's next stops are the carpenter who built the coach and the jeweler who set the gems in the coach. At the jewelers, Banacek notices a striking woman in a series of photographs and meets the jeweler himself, Mario Fratelli. Fratelli is a womanizer and a sleazy character, but he insists he told no one about his work on the coach. Meanwhile, Carlie pursues her own investigation, continually running into Banacek and withstanding a barrage of disparaging comments about her dull fiancee. When so many of Banacek's observations ring true, Carlie begins to have second thoughts. Carlie's prime suspect is Porter, the ship's first mate. He is the only crew member without an alibi when the coach vanished. Banacek discovers the man is a bigamist, trying to keep two wives from discovering each other, but he insists he did not steal the coach. When it is revealed that the ship's captain, Stavros, has heavy gambling debts, the focus turns to him. Banacek instead visits the man who was driving the truck on the docks - toy store owner Doug Sanborn. Sanborn says he was supposed to pick up a shipment and went to the wrong dock. Sanborn's wife Leona enters and Banacek immediately recognizes her from somewhere. Banacek looks around the docks at night and is almost run over by a forklift driven by Porter. The next day, as the ship is about to sail, Banacek gathers the suspects, Carlie and DeWitt together. He says that the coach will be on the ship when it sails. DeWitt insists they have searched every inch of the ship, and that the coach is not on board. Banacek says the coach was never loaded on the ship. DeWitt insists Porter is guilty. Banacek says Porter is guilty only of trying to steal the gems (he drilled the hole in the container) but he saw that the coach was empty. The solution to the case is as follows: Sanborn, with accomplices on the docks, staged the fight to distract the crew. The container with the coach had a false container around it. Hidden behind Sanborn's truck, a crane lifted the phony (and empty) container onto the boat. The real container and coach were left on the dock to be picked up later. Banacek figured it out when he recognized Sanborn's wife as the model in Fratelli's jewelery shop. Fratelli wooed her with talk of the gems and the shipment, so Sanborn cooked up the plan to steal the coach. As the police lead Sanborn and his wife away, Banacek opens the container and reveals the coach, much to Diana Maitland's delight. A fed-up Carlie calls off her engagement on the docks. A smiling Banacek offers her a ride, which she refuses. She walks off, leaving Banacek alone, but happy, in the back of the car.