It started off as a publicity stunt, a short cruise to Catalina Island on the producer's yacht for some of the cast and crew of his next film, Blue Lagoon. But when the leading lady, the exotic Zara fails to come up after a dive off the yacht, the cause of death is found to be poison. Trapped on the yacht by a thick fog, it's up to Dean Mallory, mystery author and screen writer to solve the crime, knowing that one of the passengers is the murderer. But which one? Is it the leading man, the rival actress, the mysterious central casting "Rajah," the Russian, or even the producer? And was the motive jealousy, blackmail, or something even more sinister? This-is Murder is a mystery for all fans of those classic 1930's movies.