The central twist of "Ace in the Hole" is not a sudden reveal, but a slow, deliberate act of manufactured drama by protagonist Chuck Tatum. The key turning point is when Tatum conspires with Sheriff Kretzer to reject a quick, 16-hour rescue plan in favor of a week-long drilling operation from the top of the mountain. This decision, made solely to prolong the story and build a media frenzy, directly seals Leo Minosa's fate.
As the days wear on, the festive carnival outside grows in grotesque counterpoint to Leo's deteriorating health inside the cave. He develops pneumonia, and Tatum, the only one with access, realizes his "ace in the hole" is dying. In a guilt-ridden panic, Tatum tries to reverse course, admitting his scheme to his editor and demanding the contractor switch to the faster rescue method. But it's too late. Leo dies before he can be saved.
Consumed by self-loathing, Tatum confronts Lorraine, blaming her for her part in the scheme. In the ensuing struggle, she stabs him with a pair of scissors. Mortally wounded, Tatum drives back to the Albuquerque Sun-Bulletin. He makes a final, grand, journalistic confession to his former editor, Jacob Boot, dictating the story of his own corruption before collapsing and dying on the office floor. The ending is brutally ironic: the big story that Tatum gets is his own, and he dies at the feet of the honest journalism he so thoroughly despised, becoming just another piece of "bad news" that sells papers.