A pioneer woman replaces her ailing husband in a poker game after he loses most of their money.

In 1896, the five richest men in the Laredo territory are entrenched in the back room of a saloon for their annual poker game. Seated at the table are Henry Drummond, who walked out on his daughter's wedding rather than be late for the game; Benson Tropp, a woman-hating undertaker; Otto Habershaw, a dapper lawyer who, in order not to miss the game, abandoned a client facing hanging; Dennis Wilcox, a wealthy cattleman; and Jesse Buford, a miserly local merchant. The game is still going the next day when Meredith, a timid farmer who has sworn to give up gambling, arrives in town with his wife, Mary, and their young son Jackie. While Mary goes to have their damaged wagon repaired, Meredith watches the men play cards. Unable to resist temptation, he takes his homestead money and joins the game; but by the time Mary returns, he needs an additional $500 to stay in the game. The excitement and suspense, coupled with Mary's indignation, prove too much for Meredith's heart, and he collapses. Doc Scully is summoned, and Meredith is removed from the game, but not before asking Mary to play out his hand. Although she knows nothing about poker, Mary staunchly agrees to protect the family money. She uses her poker hand as collateral and asks banker C. P. Ballinger for a loan. The other players' amused looks turn to stunned disbelief when the banker accepts the offer and raises the bet $5,000 per player. Unable to compete, the men throw in their cards and leave Mary with $16,000. They are comforted only by knowing that they have lost to a gallant and courageous woman. The men are unaware, however, that both Meredith and Mary are professional gamblers and that Ballinger and Doc Scully concocted the whole plot to cheat the big-time gamblers.