Two American's, Tommy Baldwin and Joe Dugan, are assigned to guard a fabulous diamond in Shanghai, and the diamond is promptly taken from them. They know it is being taken to a ship sailing from Shanghai to the United States, and board it with the intent of recovering the gem. Their efforts lead mostly to discovering several dead bodies but also on board is a blonde, Jane Dunn, who is an undercover agent for the U. S. Customs Agency. Maybe she can be of some help.—Les Adams