 In an unidentified airplane flying over the ocean in which six aliens are huddled, alien-smugglers Frank Barden (J. Carrol Naish) and Andrew Sleete (Buster Crabbe as Larry Crabbe) are trying to evade a government pursuit plane. They dump the screaming "evidence" into the sea. Escaping pursuit, they later approach wealthy merchant Quan Lin (Ching Wah Lee)and demand he take some aliens off of their hands. They kill him when he refuses. Lan Ying Lin (Anna May Wong), his daughter, goes to wealthy society matron Mrs. Mary Hunt (Cecil Cunningham) for help. She introduces her to an inspector and Kim Lee (Philip Ahn), a government agent. Unknown to all, Mrs. Hunt is the power behind the smuggling ring. Turning detective to catch her father s killers, Lan Ying Lin finds herself on a remote island where she takes a job as a dancer in a honky-tonk operated by Otto Hartman (Charles Bickford), and discovers the island resort is a blind for an alien receiving station. She gets the evidence on Hartman and flees the island with agent Lee, disguised as a man, in the hold of the smuggling vessel. They are discovered by the ship s captain (Lee Shumway) who radios for a sea plane. They are loaded into the plane, piloted by Barden and Sleete, and are being flown out to sea to be disposed of.