One Hour Before Dawn (aka Behind Red Curtains[1]) is a 1920 silent film mystery directed by Henry King, written by Fred Myton[1] and starring H. B. Warner, Frank Leigh and Anna Q. Nilsson.

It was produced by Jesse D. Hampton and released by Pathé Exchange.

[2] Anna Q. Nilsson emigrated to Hollywood from Sweden in 1910 to become a silent film actress, but failed to make the transition to talkies.

When she died in 1974 several American television stations interrupted their programme to show clips from her films When a hypnotist named Norman Osgood mesmerizes a man named Harrison Kirke without his consent, Kirke threatens to kill him.

Afraid for his life, Osgood hypnotizes another man named George Clayton and tells him he must murder Mr. Kirke one hour before the arrival of the dawn.