Alan Mitchell returns to New York to work for his father Walter, the owner of a fashion house that designs and manufactures dresses. To stay non-union, Walter has hired Artie Ravidge, a hood who uses strong-arm tactics to keep the employees in line.
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.
The Mayhew brothers flee from one Texas town to another as older brother Bill repeatedly attempts to keep younger brother Sam out of jail. Bill finally gives up on his younger brother and heads for Colorado. He gets a job and all is well until his brother shows up and takes a job that puts them on opposite sides of the law.
