Con man Dudley Jerico sets out to rob corrupt millionaire Victor Rosso of his legendary Gemini diamond, but there's another operator in town who is out to con the con.

After she misses her train, a young woman is forced to hitch a ride back to town. After managing to get away from a lecherous trucker, she is given a ride by a good-looking but somewhat mysterious young man, who she comes to suspect may be a dangerous escapee from a mental asylum.