Nick Burton is a convict who wields considerable influence among others behind bars. He befriends the prison doctor, Bill Collins, who is seeking a cure for a deadly virus (referred to as 'Malta fever' during the film) and needs guinea pigs for his experimental drugs. A wealthy physician sentenced for reckless driving, Harry Lindsay, is persuaded to be of help. Malta Fever is more commonly known as Brucellosis, which is a highly contagious zoonotic virus and no cure for it has ever been found.
Burton looks up two other rich inmates, Bruce Vander and Harold Kellogg, jailed for income tax evasion. They scheme to raise money for Collins' medical experiments. A pair of millionaire con men, James Brent and Sidney Keats, attempt a stock swindle even while behind bars, but Burton takes it upon himself to thwart their plans. The experiments produce a miracle cure for the virus, whereupon Burton and the doctor are both granted an early parole.