Given the question: Given the below context:  Charlie and Jimmy Chan are traveling by plane to San Francisco. Jimmy befriends insurance executive Thomas Gregory. Charlie's friend, novelist Paul Essex, dies aboard the aircraft after receiving a radiogram warning him not to ignore "Zodiac". His briefcase mysteriously disappears. Charlie meets with Deputy Police Chief J.J. Kilvaine, and runs into reporter and old friend Peter Lewis. Charlie also meets noted local magician Fred Rhadini, and discusses Essex's death with the three men. Rhadini tells Charlie about Dr. Zodiac, a psychic preying on the rich in San Francisco. Charlie, Rhadini, and Lewis go to Dr. Zodiac's home, where Dr. Zodiac conducts an eerie séance. Lewis' fiancée, Eve Cairo, has been meeting with Dr. Zodiac, angering Lewis. Later, Kilvaine reveals that Essex was poisoned, but can't rule out suicide. Jimmy spends the afternoon following Thomas Gregory, whom he believes stole Essex's briefcase when leaving the plane. He discovers Essex's manuscript in Gregory's hotel room. That night, Charlie attends Rhadini's magic show at the Golden Gate International Exposition on Treasure Island. Rhadini's clumsy, comic acquaintance, Elmer Kelner, is helping to serve food and drink at the club. Charlie meets Eve Cairo and socialite Bessie Sibley, as well as Rhadini's jealous wife, Myra. During her telepathy act with Fred Rhadini, Eve comes into contact with someone thinking about murder and Charlie is almost killed when a knife is thrown at him.  Guess a valid title for it!
The answer is:
Charlie Chan at Treasure Island