Arno's master is murdered by an unknown assailant, and Bob Blake, a brutal ruffian, takes possession both of the dog and of the late owner's cabin. Arno despises Blake and runs off, seeking protection with Dave Wright, a kindly doctor. Polly Ann Hadley, the dead man's niece, arrives on a visit to her uncle and goes to the cabin now occupied by Blake. Blake seeks to defile her, but Arno comes to her aid, keeping the lecher at bay until Dr. Wright appears. Blake is proven to have killed Arno's master, and Dr. Wright woos and wins Polly Ann.