Buchanan 17: Buchanan's Gun

It was hot enough to burn rawhide, and lizards were frying on flat rocks. It was, Buchanan decided, just about two degrees fiercer than hell, and if he could keep going for another half an hour he’d allow himself a drink from his canteen.
He was in a mood for comfort, so naturally he got trouble.
He came on the troop of cavalry conducting an army prison wagon, and in the wagon he discovered his old friend, the Apache chief, Sentos, with three of his braves. It was well over a hundred and twenty degrees in the wagon. “What happened, viejo?” Buchanan asked Sentos.
“I was stupid,” the Apache said, “I trusted a blueleg warrior, and he betrayed my flag of white. Now they wish to hang me.”
Buchanan looked at the troopers and sighed. He couldn’t let them hang a friend.