Travel author Leslie Sears arrives in Cairo, Egypt, to meet with Greg Stewart, an old war buddy who is a theater booking agent in Port Said. Leslie telephones Greg and arranges a rendezvous, but shortly after the conversation ends, Greg is murdered. Unaware that his friend has been killed, Leslie goes to the Hotel Siwa, where Greg was staying, and finds a blonde woman searching through Greg's belongings. The woman, Gila Lingallo, escapes, and later meets Jakoll, the man who murdered Greg and dumped his body in the river. Gila berates Jakoll for murdering Greg, and tells him that she only wanted Jakoll to keep him away long enough to search his room for evidence that might incriminate her and her father, the magician Paolo Lingallo. Leslie, meanwhile, becomes concerned about Greg's disappearance and begins an investigation into the matter. At the Café Daghla, Greg's friend, Bunnny Beacham, suggests that Leslie visit Alexis Tacca, the man who leased his theater to Greg. When Tacca takes Leslie to the theater, shots ring out from behind the billboard advertising The Great Lingallo's show. Leslie manages to escape injury, and when he returns to the hotel, he learns that Greg's body has been found in the canal. Leslie finds Gila and accuses her of breaking into Greg's room, but she denies the accusation and tells Leslie that she can prove that she and her father were in an airplane at the time of the murder. Late one night, Gila finds Jakoll in her room preparing to kill her, but her screams frighten him away. A short time later, Paolo tells Leslie that his niece, Helena Guistano, who resembles Gila, and Helena's father Mario were Nazi collaborators. Paolo also admits that he has followed the Guistanos to Port Said hoping to familiarize the townspeople with Gila's face so that Helena will be mistaken for Gila and captured. On the basis of Paolo's story, Leslie concludes that Greg was killed by the Guistanos for attempting to book Paolo's show at the Ramses theater. Later, Leslie and Paolo take Gila to the Daghla Café, and Bunny notices the similarity between Gila and Helena, but when he tries to tell Carlo, the club owner, he realizes that Carlo is one of Mario's men. Carlo sends Jakoll to kill Bunny, and the murder is witnessed by a young woman who was waiting for Bunny. After Jakoll's tries unsuccessfully to kill him, Leslie attends a rehearsal for the magic show. There, Mario's men knock Leslie unconscious, drug Gila and replace her with Helena, who has changed her hair color to match Gila's and is planning to kill Paolo during the show's sword fight. As the show begins, Leslie regains consciousness and rushes to the theater. At the same time, the woman who witnessed Bunny's murder finds Jakoll with Gila and stabs him. Leslie arrives at the theater in time to prevent Paolo's murder, and Mario and his accomplices are arrested.