Roy Hobbs is a talented baseball player from the countryside with a homemade bat christened "Wonderboy," carved from a tree struck by lightning. As a young man, he impresses onlookers with his remarkable pitching skills. Dreaming of baseball stardom, Roy is on his way to try out for the Chicago Cubs when a mysterious woman, Harriet Bird, catches his eye on the train. After showcasing his prodigious talent in a brief stop at a carnival, he captivates Harriet with his potential. However, their encounter takes an unexpected and tragic turn that derails his aspirations.

Years later, Roy re-emerges as a middle-aged rookie with the New York Knights, a struggling baseball team managed by Pop Fisher. Despite his age, Roy's natural abilities shine, and he quickly becomes the team's beacon of hope. Off the field, Roy is drawn into a world of intrigue and temptation, including the machinations of a team owner with dubious intentions and a sports journalist, Max Mercy, who is determined to uncover the enigmatic past that Roy so fiercely guards. Meanwhile, a figure from his long-lost youthful aspirations re-enters his life, offering both distraction and inspiration. As he battles adversaries and personal demons, Roy strives to fulfill the potential that has long been dormant within him, fighting for a shot at baseball glory that once seemed assured.