Hollywood, 1951. Jack Shannon—hobo, rising star, wounded vet, studio publicist—is in exile. Blackballed by the majors for his unauthorized effort to solve the mystery of a sexpot actress’ disappearance, he’s now a stuntman—a drug-store cowboy working from Tinseltown’s Poverty Row, where the budgets are tight and the jobs scarce.

As the work dries up, Jack is in danger of losing his home, but salvation arrives in the figure of Karen Scott, a star who needs help as much as Jack needs money. Years ago, she found herself homeless in Hollywood. In her desperation, she agreed to appear in a stag film, and now, someone has mailed her a snippet of that long-forgotten film. She expects a blackmail demand to follow, and she’s come to Jack for help. He handled this sort of thing as a publicist at Titanic Pictures, and she’s willing to pay him big bucks.

Jack has barely begun his investigation when the blackmail demand arrives: $50,000 in exchange for the negative. He reluctantly agrees to handle the pay-off for Karen, but when he arrives at the appointed spot, he finds a dead man seated behind the wheel of a car and is himself knocked out from behind. When he comes to consciousness, he discovers the blackmail money gone, no sign of the negative, and himself the major suspect in the murder.