When Commanches go on the warpath, settlers take refuge in Ft. Eagle Rock commanded by Capt. Jackson. Undercover agent Cliff McPherson arrives at the undermanned fort to lend advice and support. He learns that the Commanches have been stirred up by local rancher Morton who wants to take control of the oil under the Indians' reservation. McPherson informs Chief Black Eagle of Morton's treachery and the Indians then ride to the rescue of the cavalry when Morton's men attack the soldiers and settlers fleeing the fort.