Having had enough of leading a fairly large brigade of trappers, giant mountain men Nathaniel Squire heads to the Rockies with just a few of his young friends. The small group is having a fine season, pulling in plenty of plews. But another group happens by and tells Squire that last year's brigade, under Colonel Leander Melton, is in dire straits, having been raided by the Blackfeet under the direction of Jacob Meisner, an old enemy. Squire and his group plunge headlong into an effort to save Melton and his brigade -- and then, one way or the other, take to the vengeance trail.