The Danger Trail (UNABRIDGED)

Chicago engineer Jack Howland is sent to the edge of the Canadian barren lands north of Prince Albert to establish a train route through some of the most trecherous terrain in North America. He would soon learn that it was not only the terrain that was forbidding, as he begins to understand why the previous engineers sent on the same mission had been forced to give up the task and flee back to the south.
Mysterious visitors, suspicious characters, strange apparent coincidences, and one particularly mysterious girl meet Howland at every turn in this suspenseful tale of adventure, excitement, danger, and romance set in the northern Canadian wilderness. (Summary by Roger Melin)