In New York the weights and measures inspectors make sure citizens are not short changed. Small cheats lead to big profits and thus the inspectors are under fire. Johnny (Cagney) is put in charge of the department after the head is put on the shelf in a suspicious accident. Johnny discovers that everyone in business wants to be his friend, and want him to look the other way in return for a bribe.
Even though Johnny plans to marry Janet (Mae Clarke), he remains firm. Though unfortunately one of the crooked businessmen is Janet's boss and this soon puts his relationship under trouble as well as his safety...
This is a great little film, one of a couple of B-movies Cagney made for smaller studios when he was between major studios. His character is maybe a little too good to be true at times but Cagney pulls it off in his usual energetic and charismatic style, of course.