A shy comic book fan is injected with an experimental serum and starts turning into a spider. When web covered bodies start appearing a policeman starts to investigate the strange case.

In 1910, John Flinders is warden of Red Rock Territorial Prison, in Arizona. When a condemned man's last request brings Flinders into contact with the man's widow, Flinders finds himself falling in love. Meanwhile, a new convict, Mike Sullivan, turns out to be an old friend of Flinders'. They talk over old times, but it's clear that Sullivan has plans to leave the prison before his time is up. When those plans come to pass, Flinders sets out to re-take his old pal.