'Why Not' is the 312th episode of Gunsmoke. In this episode, Marshal Matt Dillon faces a critical moral dilemma when a criminal he once captured is released from jail. The criminal seeks vengeance against Dillon, prompting a tense confrontation that questions themes of justice and redemption. As the plot unfolds, Dillon must reconcile his duty to uphold the law with the personal stakes involved in facing an old adversary.