Mystery, suspense, with a touch of romance. On the opening night of Helen Hardwick’s play, a chilling murder takes place in the Thelma Theater. The victim utters the name “Mr. Shei” as she laughs maniacally and dies. The only clue to her death is the mark of a hypodermic needle on her arm. Mr. Shei, a diabolical criminal, has been terrorizing the city and eluding the police. Helen seeks out the one man who can find Mr. Shei and bring him to Justice - The Gray Phantom. But when Helen arrives at the Gray Phantom’s isolated estate, she finds it has been sold to a mysterious and dangerous man, who takes Helen prisoner. Helen learns that the new owner and her captor is none other than Mr. Shei, and that he plans to inject her with the same poison that was used on the victim at the theater.