Jess's brother-in-law, an Army deserter, shows up looking for help to reach Canada via the Lola Pass. Slim is against Jess helping so he refuses to share his map of the trail. However, he relents under pressure against his better judgment.
After receiving a beating at an Army post, Private Gil Brady shows up at the Sherman Ranch Relay Station beaten and half-starved looking for help from his brother-in-law, Jess Harper. Gil claims he is the victim of an abusive sergeant because he is from the south and was in a battle in which the sergeant's relative was killed. He has deserted from the Army. He wants Jess to take him to Canada by way of the Lolo trail to meet up with his wife, Francie, which puts Jess at odds with Slim Sherman. Slim has a map of the difficult and dangerous trail but he refuses to give it to Jess and Gil. Determined to get Gil to Canada for his sister's sake, Jess sets off with Gil. Ultimately under continuing pressure from Jonesy and Andy, Slim joins a chase that could cost Jess his life. The furious Sgt. Abe Jordan along with Indian scout Areka both on Gil's trail arrive at the relay station knowing Jess is his brother-in-law.