Pop Clark, David Landau, owner-manager of the St. Louis Cardinals, sits down with newspaperman Jimmy Downey to take stock of a season that started as a favorite yet has slipped into trouble. He reveals a bold move: he has signed star pitcher Larry Kelly, Robert Young, hoping one standout ace can seal the pennant. Kelly arrives amid flirtation and friction, striking a chord with Frances Clark, Madge Evans who works in the front office as team secretary, and then suiting up for practice. On the field, catcher Hogan, Nat Pendleton — often at odds with umpire O'Toole, Ted Healy — becomes a flashpoint as Pop chases away two former players tied to organized gambling who try to recruit the team. Pop insists the club will stay clean and tells the players to steer clear of any gambling influence, even as he confides to Frances that a pennant may decide his future: if they don’t win, the franchise could pass to Henry Ainsley, John Hyams, after Pop borrowed every penny to hire Kelly.
Reporter Downey spots Joe Karnes, C. Henry Gordon, in the stands and threatens to print a story about his gambling links, increasing the pressure from the underworld. Karnes offers Kelly a ride to a team dinner and invites him to visit his yacht, though Kelly declines to break training. At the dinner, Downey reveals Karnes’s gambling prominence, and Mickey Rooney, Mickey Rooney, bursts in with news that someone tampered with the gloves in the clubhouse by applying a chemical designed to incapacitate players. Suspicion rises, and Spencer, the team’s star hitter, accuses Kelly of taking advantage of the scheme, though Frances forces the two to settle things for the moment. The team then faces a stern test: Ainsley taunts Pop at a home game, while Karnes and his men keep a close watch from the stands. Kelly answers with a brilliant performance, and Spencer delivers a walk-off hit that hands the Cards a victory and lifts them to a strong standing.
With the Cardinals now in second place, Karnes and his peers confront the mounting risk of a ruined payoff. In a hotel room, Kelly discovers an envelope containing $10,000 and a note claiming a “friend” hopes he will lose the next game. The squad, along with Downey, grows wary and resolves to uncover who is behind the money. The next day, Kelly again takes the mound against the Reds, and this time he pitches a no-hitter in a game that puts pressure on the gamblers. As he and Hogan ride back in a taxi, a hidden rifle shot blows out a tire and they crash; Kelly is injured and sidelined for two weeks. In the hospital, the team’s doctor announces that Kelly should be sent home to recover, but Downey bursts in with the news that the police have found a bullet hole in the taxi.
Despite Kelly’s absence, the team continues to shine, and after 151 games they surge into first place in the National League. With three games remaining, they must win two to clinch. On a train home, Kelly and Spencer quarrel over Frances, and Ainsley quietly instructs a man to disembark at Springfield without explanation. In the next matchup against the Chicago Cubs, the Cardinals tie the score in the 6th, but Karnes’s men execute a quiet order that shifts the momentum. In the bottom of the 8th, with two outs and two on, Spencer delivers a key hit, the tying runs score, and then tragedy strikes: Spencer is shot as he rounds home, and the Cardinals lose the game.
Police questions follow, focusing on Kelly’s absence and the train quarrel with Spencer. Kelly insists he wasn’t avoiding Spencer’s moment of glory; he simply didn’t want to “take a bow” at a moment that might endanger others. Downey presses Karnes for more information, but Karnes remains defiant, threatening the journalist before walking away. The sport’s drama thickens as the Cardinals prepare for more games while the investigation narrows toward the endgame: a final showdown against Cincinnati.
Before the final match, wives and girlfriends plead with the players to stay safe. In the clubhouse, security scrambles to keep Karnes’s crooked men away. As Higgins—Robert Livingston as Frank Higgins with Higgins warming up to pitch—goes inside the clubhouse to take a call, he disappears. Pop summons Warmack to the mound in a tense moment, only to discover Higgins’s body in a locker: he has been strangled. The team rallies, and Warmack delivers a solid performance, but the game’s outcome hinges on late drama.
A distraction near the end leads to a dramatic sequence where Hogan, after eating his usual hot dog, falls ill and dies just as a detective probes a tip about a call for Higgins. Downey’s suspicions refocus on Patterson, the trainer, DeWitt Jennings whose jealousy and fear seem to surface at pivotal moments. Patterson attempts to use force, but he’s overpowered and confronted with the truth: his envy and fear of Pop’s control over the team pushed him toward violent acts.
The final game against Cincinnati ends on a razor’s edge. Kelly returns to prove himself, and on a climactic moment Pop’s instinct pays off: he lets Kelly swing, and the ball sails over the outfield for an inside-the-park home run. O'Toole, Ted Healy behind the plate, calls the play correctly as the winning run crosses the plate and the Cardinals clinch the pennant with a 3-2 victory. Pop confronts Ainsley about the earlier promise to install Patterson as manager, while Downey explains his growing suspicion of Patterson to Kelly and Frances. The film closes with Kelly and Frances sharing a quiet kiss, and Downey warning him not to strain his arm before the World Series arrives.
