In The Big Con, the story unfolds in the bustling town of Dodge City, where U.S. Marshal Matt Dillon is accustomed to the dangers that lurk in the shadows. One morning, Dillon finds himself at the bank, a rare occurrence for him, which raises concerns for his friend Chester. The atmosphere is tense as a gambler named Hook enters the scene, seeking a hefty loan of twenty thousand dollars to cover his debts from a poker game. The stakes are high, and Dillon senses trouble brewing.