Hollis Don Knotts is an earnest but not very sharp man whose life revolves around simple pursuits and sincere friendships. His closest companion is a dedicated sanitation worker, and his romantic interest is Ema Letha, a charming and earnest waitress at the diner across from City Hall, where Hollis works as an accountant. The story unfolds in a small town where the local political landscape is as colorful as it is corrupt.
The town's mayor, along with his staff and the wealthiest man in town, Mr. Spaulding, realize they need to cover up their widespread embezzlement. To do this, they decide to eliminate three out of four accountants working in the basement and replace them with a large computer named LEO (Large-Capacity Enumerating Officiator). Hollis, being the seemingly dimmest of the group, is kept in the dark and assigned to operate LEO, despite his limited understanding of technology. As the computer processes data, Hollis unexpectedly uncovers discrepancies in the city's road work budgets, which sets off a chain of events exposing the corrupt schemes.
In an effort to buy Hollis's silence and keep him from revealing their crimes, the mayor and his associates promote him to the "third floor," where he is distracted with a shiny new Cadillac and a seductive secretary, Yvonne Craig, who skillfully manipulates him into signing documents and checks. Meanwhile, his girlfriend Ema becomes increasingly suspicious of the strange new developments and the people around him.
The plot thickens when the Assistant Bill Quinn, the Assistant State Attorney General, starts to investigate the suspicious activities of the Dalton City Council. Hollis, having signed many documents unknowingly, becomes the prime suspect. To escape arrest, he disguises himself as the mourning mother of Mr. Spaulding, who has apparently died under mysterious circumstances. Using this disguise, Hollis infiltrates City Hall to recover crucial evidence from LEO—the computer’s memory bank—which has mysteriously gone missing along with Spaulding's body.
His suspicion grows when he discovers the body of Spaulding in a closet and notices that the memory bank has been secretly hidden within the coffin of the deceased. Hollis and his loyal friend hatch a plan to exhumate Spaulding's coffin and connect LEO to retrieve the stored data. When they finally do, LEO unexpectedly explodes, scattering IBM cards everywhere. Carefully examining these cards, Hollis discovers encoded evidence that proves his innocence and exposes the corruption at the heart of the town’s government.
Towards the end, Hollis and Ema are rewarded with a honeymoon trip to Rio de Janeiro, generously paid for by a grateful city. As the happy couple admires the breathtaking view from their hotel balcony, they share their hopes for a fresh start. However, the story takes a comic yet dark turn as the hotel staff, who appear to be disguising the mayor and his cronies, discreetly remove Spaulding’s dead body from the room on a dolly, hinting that the town’s corruption is far from over and that some schemes remain hidden beneath the surface.
This film is a charming satire that combines comedy, crime, and a touch of the absurd, highlighting how earnest innocence can sometimes collide with the corrupt underbelly of politics, all wrapped in a lighthearted, humorous tone.
