They don't really take their job as lawmen seriously. In fact, when they find their old partner again (Sam--played by Lloyd Nolan), they make plans to warn him of Ranger activity, tell him about impending gold/money shipments, and secretly help him in other ways.
But a funny thing happens as time goes by. The two men can't help but admire the bravery of their fellow Rangers. One of them meets a pretty girl, who admires him as the man she only thinks he is. The other discovers he enjoys having a young orphan he rescued from Indians look up to him.
It takes awhile and MacMurray's character is especially reluctant to change, but the two men eventually realize they like being good guys.
But then, they are assigned to bring in their old friend Sam. Where do their loyalties lie--with the Rangers or with their old friend?
This is another great Western. For those of us who grew up knowing Fred MacMurray primarily as the father on My Three Sons, it's always fun to watch him play a tough guy role and do it well. Because, by golly, Chip and Ernie wouldn't have gotten away with any of their shenanigans if MacMurray had still been packing a six-gun! Uncle Charlie wouldn't have been so smart-mouthed all the time, either.
The supporting cast is strong as well. Lloyd Nolan combines charm and ruthlessness as Sam and Gabby Hayes has a brief but fun role as the sort-of corrupt judge of a Texas town. King Vidor is the film's director and gives us several magnificent action sequences, particularly a scene in which a few Rangers are trapped on a cliff-side by Indians waiting below them, only to have more Indians begin to roll boulders down on them from above.