Bowery Boy: Dr. Tom O'Hara takes over a public clinic in New York's desperately poor Bowery section. Boy gangleader Sock Dolan resents Tom's interference in moving Sock's kid brother to a hospital, because Sock blames hospitals for his mother's death. Sock helps racketeer J.R. Mason sell food to the clinic, unaware that Mason sells cheap and often tainted food. When a number of patients, including Sock's brother, become ill from food poisoning, Sock is kidnapped by Mason to keep him silent. Dr. O'Hara must find a way to rescue Sock and stop Mason's contamination of hospital food supplies.