The film was made and released about two years after its source novel "The 13th Man" by Murray Teigh Bloom had been first published in 1977.
After working with her when he directed Flotte Sprüche auf Kanal 9 (1977) (Fighting Mad), Jonathan Demme cast Lynn Lowry to co-star in this. She signed the contract and was then brought in to meet Roy Scheider and get fitted for wardrobe. But the next day, her agent called and said Scheider wanted to use his girlfriend Janet Margolin in the part instead. The producers dropped her against Demme's wishes but she still got paid and continues to earn residuals from it.
Many major movie posters for the film featured a blurb that read: "It begins with an ancient warning. It ends at the edge of Niagara Falls. In between there are 5 murders. Solve the mystery. Or die trying".
Miklós Rózsa score for this film was composed in the style of Bernard Herrmann who worked regularly with thriller director Alfred Hitchcock. This film's composer Rózsa had worked with Hitchcock himself once, on Ich kämpfe um dich (1945).