Duncan MacDonald, a 19th-century Royal Canadian Mountie, has to escort a group of Cree Indians back to their above-the-border reservation. His guide in this endeavor is the not-too-trustworthy half-breed Natayo.

Bud Corliss (Wagner) is an ambitious student who is wooing Dorothy Kingship (Woodward) purely for her father’s mining fortune. When he discovers that Dorothy is pregnant with his child, he realizes she is quite likely to be disinherited by her wealthy family. He assures Dorothy that he’ll take care of her, yet he hesitates when Dorothy insists on marrying. Bud then murders Dorothy and stages it in a way that it appears to be a suicide. He then reaches out to her sister Ellen (Leith) with the hopes of marrying her in order to ingratiate himself with her father. After a couple of months Ellen finds evidence to question the suicide verdict, and then discovers Bud knew Dorothy. Ellen struggles to avenge her sister and save her own life.