Flying Fists plot
Amateur boxer Hal Donovan fights prize fighter and former heavyweight champion Slug Cassidy at a logging camp. Slug is defeated and his trainer Spider asks Hal to become a professional boxer. Hal agrees and he becomes a successful boxer under the name 'Chopper'. Hal meets young Dickie Conrad and his attractive older sister Kay, who cares for her boxing-crippled father. Kay, who knows nothing about Hal's profession, hates boxing. When Spider and Dickie discuss Hal's profession with Kay, she breaks up with Hal. Hal becomes bitter because of this and leaves the sport of boxing. During his vagrant existence, Hal learns that Spider has hired Lion Lee as his successor.