With the herd dying of thirst, Favor must decide whose advice to follow — Rowdy’s advice to head west or that of Lou Bowdark, the new hand, to cross the San Marcos, a treacherous desert. Going east is considered out of the question. There is no sign of water either way, but Rowdy likes the gentle looking trail to the west. What initially decides the issue for Favor is the strong conviction expressed by Bowdark, the mustang hunter who has lived alone in the area for many years and has just joined the drive. What they do not know is that many years earlier Bowdark was trail boss of another herd which traveled through the San Marcos and ended up as a massive cattle graveyard. Bowdark finally owned up to it, but becomes unglued and insists that the disaster was caused by his gutless drovers, and now recklessly wants a second chance to vindicate his misjudgment.