While on a hunting trip, Lucas and Mark becomes separated. During his search for Mark, Lucas stumbles onto the notorious Skull Ranch, a headquarters for many vicious outlaws in the New Mexico territory. The outlaws refuse to let Lucas leave, insisting that he will have to accompany them to town and assist them in breaking out two of their comrades from jail. Lucas tries to refuse, but changes his mind when he learns that the Skull men have found Mark and have taken him prisoner. He is to be the guarantee that Lucas will cooperate in their deadly plan. Mark, however, makes an escape and gets to town in time to warn the Sheriff, and Lucas is able to turn the tables on the Skull gang.