Based on a play by Milhauser and Dix, a boxer accidentally kills a reporter; but when police believe he is dead, he escapes to fall in love at a charitable ranch.
Boxing champion Jimmy Dolan (Douglas Fairbanks Jr.) presents an image of no drinking, no women, and talking to his mother, because he believes people are suckers. He is drunk with Goldie when her friends come over with his manager Doc (Lyle Talbot). Jimmy admits he has no mother, and a reporter plans to write the story. Jimmy slugs him, and the reporter dies, as Jimmy passes out. Doc takes Jimmy's money and watch, leaving with Goldie. They drive fast and are chased by police. Their car crashes and burns. Jimmy wakes up to read in the paper that Jimmy Dolan is dead after murdering a reporter. Jimmy goes to his lawyer, who tells him to stay dead, taking $10,000 out of the bank for him, but leaving him with only $250. Phlaxer (Guy Kibbee), a detective who sent an innocent man to execution, tells the inspector the dead body was not Dolan because the watch was on the wrong arm; but they laugh at him.
Jimmy becomes Jack and rides freight trains and walks until he collapses at a ranch house. Peggy (Loretta Young) takes care of him, and he kisses her. Jack stays to work, and Freckles (Mickey Rooney) shows him how to milk a cow. Peggy tells him they treat crippled children; but they need $2,000 by the 30th, or the kids will have to go back to the institution. Phlaxer sees a newspaper photo of Jack a kid took. Jack admits he loves Peggy; but he says she is a sucker for helping the kids. Jack decides to fight King Cobra for $500 per round, and he trains. He sees Phlaxer looking for him and thinks of leaving; but Aunt (Aline MacMahon) gives him a boxing robe; the kids give him trunks; and Peggy gives him a kiss. Jack will fight right-handed. Aunt secretly goes to the match, while Peggy and the kids listen on the radio. King Cobra knocks out Primaro and Smith (John Wayne). Phlaxer calls Jack "Jimmy." Jack boxes Cobra and is knocked down several times; but he manages to make it to the 5th round before he is knocked out. Peggy cries over him, and he tells her he has to go, saying Phlaxer is his manager. She wants to go with him; but Phlaxer takes him to the train. Phlaxer calls Jimmy a sucker but then says he got the wrong guy, leaving Jack behind.
Adversity and friendly people in a rural setting help a cynical urban boxer to learn about idealism and caring for others. Even the detective passes up a chance to redeem his reputation so that Jack can continue his new life.