Paladin, hired by the barber/surgeon of a small California town finds himself caught up in a curious romantic rectangle involving the barber, an attractive young woman, and two macho bachelors who, like testosterone-fuelled bucks, are determined to win her by engaging each other in sporadic combat with their long guns.The Lady of course is interested primarily in the barber but has deeply personal reasons for wishing he'd show some backbone and take up a rifle himself.
Paladin arranges a four-way shootout involving himself and.the other three men, with the survivor collecting the money they wager (in advance) on the outcome. And the "outcome" sees Paladin giving the spectator-townsfolk a brief lecture on the nature of Courage.
Interestingly, the phrase "Survival of the fittest" (which plays a key role in this episode) was not actually coined by Charles Darwin but by one of his admirers. Darwin eventually acknowledged it as being more convenient to use than than the wordier (if more accurate) ""better adapted for the immediate, local environment".