Based on The 13th Man by Murray Teigh Bloom, this is a hell of a role for Roy Scheider, who plays Harry Hannan, a government agent whose job intrudes on his family life, as an informant appears too early — Joe Spinell appearance! — and the ensuing gunfight takes the life of his wife. He spends five months in an institution and worries that he’s being frozen out by the agency and has become expendable.

When he goes back to his apartment, he finds that Ellie Fabian (Janet Margolin) is living there. A note has been left for him under the door. It’s in Hebrew and reads “Avenger of Blood.” Meanwhile, as he visits his wife’s grave, he fights with her brother, Dave Quittle (Charles Napier). Despite being told that he’s safe, Harry is marked for death by Quittle and his boss, Eckhart (Christopher Walken).

Between having to deal with people trying to kill him at every turn, he works with Sam Urdell (Sam Levene) to solve the notes that he’s been left.

“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.” What a tagline. Director Jonathan Demme cast Lynn Lowry as Ellie in this, but Schneider wanted his girlfriend, Janet Margolin, in the movie. The producers dropped her against Demme’s wishes, but she still got paid and continues to earn residuals from it.

This is a Hitchcock cover from start to finish, even having Miklós Rózsa do the score. He worked with Hitchcock on Spellbound. And the end, while darker than North by Northwest, is similar. Yet this surprised me; between how raw Scheider is and the darkness of the murders, it’s excellent.

You can watch this on Tubi and get it from Vinegar Syndrome.