In San Francisco, Sylvia Douglas and her fiancée, James Callahan, a reformed crook, make their getaway after Jim, disgusted with his inability to find a job, un-reforms and steals a diamond necklace. Graham, a detective, gives chase to a desolate island in the South Pacific where a rum-running gangster, Murdock, holds him captive. Callahan becomes infatuated with a native girl, Leona, and Sylvia turns to Graham for protection against the offensive Murdock. A volcano eruption causes problems for all.