This version changes the ending of Mark Twain's classic novel about an independent boy, who runs off with a slave.
Huckleberry Finn (Mickey Rooney) misses school to fish and smoke a pipe. Students tell him he won't be promoted. Huck arrives late for dinner and agrees with the suppositions of Miss Watson (Clara Blandick) and Widow Douglass (Elisabeth Risdon). Their slave Jim (Rex Ingram) tells Huck he is saving money so he can go to his wife in a free state. Huck tells Widow Douglass he smokes and tells lies because he can't stand wearing shoes. Huck finds his Pap (Victor Kilian) in his room. Pap objects to Huck learning how to read and asks Widow Douglass for $800. Huck leaves and goes with his Pap. Huck takes things, shoots his hat, and goes in a boat. He finds Jim running away, because Widow Douglass was going to sell him. At night Huck dresses as a girl, goes into town, and learns that men want Jim for his murder. In rain Huck helps Jim flee. On a raft they head for Cairo.
Huck "borrows" a watermelon and eggs. Two swindlers are thrown off a steamboat and get on the raft with Huck and Jim. They say they are a Duke (William Frawley) and a King (Walter Connolly) hoping to inherit money. They advertize a play and see a reward for Jim. King plays Romeo and Huck Juliet, but Huck is exposed. King and Duke pretend to be brothers of the late Peter Wilkes with Huck as valet. Susan Wilkes (Jo Ann Sayers) and Mary Jane Wilkes (Lynne Carver) welcome their uncles. King gives Susan and Mary Jane the $2,000 in gold so they can sell the estate. Huck objects but goes along. Captain Brandy (Minor Watson) calls them impostors; but Mary Jane gives the money back to King. While King and Duke sleep, Huck takes the money and puts it in the coffin. Huck tells Captain Brandy, who is an abolitionist and offers to take Jim on his ship. Huck tells Jim he is going to be free, and Jim says that Huck's Pap is dead. Crying Huck says Jim is not his friend for having held it back. They run from dogs. Huck is bit by a rattlesnake, and Jim carries him to a doctor.
King and Duke are tarred and feathered. Captain Brandy tells Susan that he sent Jim back for murder. In his trial Jim says that Huck is alive. In bed Huck learns from Susan that Jim is in jail. Captain Brandy finds Huck running in the rain and takes him by ship. A mob threatens jailed Jim, but Huck arrives to save him. Huck asks Widow Douglass to free Jim and agrees to go to school, wear shoes, and stop smoking. In the final scene Huck waves good-bye to Jim on Captain Brandy's steamer and walks off barefoot with a pipe.
The melodramatic ending reflects the real danger of lynchings still existing in the South in the 1930s, and Twain's story expresses the natural tendency of many boys to rebel.