Chuck, a reporter for The Blade newspaper, gets beaten up while trying to get a story on prison corruption, and the rest of the Bowery Boys, Slip, Sach, and Butch, get themselves arrested so that they can complete the expose from inside the prison, while serving a short---they think---six month sentence. Inside the Big House, they learn that ex-gangsters Ed Lannigan, Tom Tomcyk, and "Big Greenie", are living in the lap of luxury within the prison, by paying off Jenkins, the corrupt Captain of the Guards. And, on the side, the Boys, Sach in particular, slowly send Dr. Fordyce, the prison psychiatrist, off the deep end as they clumsily go about their investigation.