A mission to Venus discovers the planet inhabited only by women led by their evil Queen Yllana. Yllana had all the men of Venus killed, now that's she met Earth men, she wants them dead, too.
An agent from a distant planet has been sent to earth to ship large quantities of blood to his world, where a plague is ravaging the populace. He comes equipped with an interstellar matter transmitter, telepathic mind-control powers, and deathray-shooting eyes. Because he is also affected by the blood disease, he gains control of the town's physician and has him place a nurse at his disposal, while he collects live humans for fresh blood; but gains the nurse's suspicions, along with those of her boyfriend - a town police officer.