A fire in the mountains drives a wolf pack into the nearby desert where they terrorize the local residents. The leader of the wolf pack is Lobo, actually a halfbreed (Rin Tin Tin). When the pack is discovered hunting a herd of cows, a posse gives chase. Lobo leaves his pack to lead the posse away. He is injured and found by a local prospector, Dave Weston (Charles Farrell). The prospector nurses Lobo back to health and the two become close friends. Meanwhile, Weston has made a Borax find in the area. His girlfriend May Barstowe (June Marlowe), daughter of a wealthy rancher, is pleased. However, the local chemist, Borax Horton (Pat Hartigan), actually a claim jumper, plans to steal the claim.
Rin-Tin-Tin
as Lobo - Leader of the Wolf Pack
Nanette
as Lobo's Mate
Charles Farrell
as Dave Weston
June Marlowe
as May Barstowe
Heinie Conklin
as Alkali Bill
Will Walling
as Sam Barstowe
Pat Hartigan
as Wm. 'Borax' Horton
