Mounted Police Sergeant MacKenzie investigates a series of "ghost" killings in the Valley of Lost Souls near Lachine, Quebec, Canada. He meets Julie Lebeau, who has recently rejected her suitor, Jacques. Unaware that Jacques is the killer, MacKenzie accepts his offer to serve as a guide. However, when Jacques learns that Julie and MacKenzie have fallen in love, he dynamites a hut where the sergeant has taken shelter. Although MacKenzie escapes the blast, he is knocked unconscious in the ensuing fight. Jacques returns to the trading post to kidnap Julie, but MacKenzie arrives with his aide and bring Jacques to justice.—AFI