Department of Weights and Measures Inspector Johnny Cave finds himself in the midst of deceitful government officials when he takes over for his boss, whom the officials have beaten and put in the hospital.

Cave quickly acts to turn everyone in, but his corrupt counterparts refuse to go quietly. Soon he exposes the hidden government agenda that has his coworkers bilking the American taxpayers out of several thousand dollars per year by stealing an equally small amount from everybody.

Although he's on the right side of the law, he has to rely on more than righteous words when it comes to saving his own neck. The villains manage to frame him on a phony blackmail charge that taints the public's view of Cave. Now he not only has to clean up the bureaucracy around him, but he must clear his own name, too.

Cagney's appearance in "Great Guy" ended a year-long absence from film. The Warner Bros. brass had decided to lay Cagney off because of the long legal skirmishes that resulted after his contract expired the prior year. He allegedly received numerous telegrams praising his return to the screen.