The plot and subplots center on the movie's leading man, Paul Harris, a divorced high school teacher and basketball coach and his interactions during a killer rat infestation with a health department inspector, Kelly Leonard, a high school cheerleader, Trudy White, his friend a professor and rat expert, Dr. Louis Spenser, and his students. Giant rats the size of small dogs living in mountains of grain full of steroids are rendered homeless when Kelly orders it to be burned down. The Rats migrate to a suburban home occupied by unsupervised high school students. The rats begin to kill a toddler left unattended in a high chair. Henry Younger, a senior citizen was attacked by the rats, walking the snowy streets alone late at night. George Foskins, a health department field inspector, is destined to become the next victim. Inspecting the bowels of the city's sewer system, he encounters a pack of the rats. George commences with 'the running of the rats' in the sewer, followed by his demise. Paul telephones his friend, Louis, who instantly concludes that the steroid feed had spawned a new breed of 'super-rat' that had migrated into the sewers in search of food. Upon hearing this information, the Health Inspector immediately orders the fumigation of the entire city sewer system, which is immediately and efficiently carried out with no apparent effect. The futility of this action is confirmed when the rat expert himself is attacked and killed. The rats then move on to a bowling alley and a movie theater and make their first brazen mass attack on the unsuspecting public. The rats select the viewers of a Bruce Lee movie, resulting in numerous deaths, including Trudy, and a scene of fleeing film patrons. Meanwhile, the city's mayor, Rizetti, prepares to make an inaugural run of a new subway section—straight into a hungry pack of rats. While escaping the rats, and sacrificing the other delegates, Mayor Rizetti stows away on the empty subway train. Paul attempts to stop the festivities. He is forced to assault a cop and take his revolver. Paul proceeds down the tunnel and finds a disabled subway train, with passengers just emerging from the cars. Paul finds Kelly and his son just as the rats attack the passengers and Mayor Rizetti is killed by the rats off-screen. The three are able to escape down the tunnel and find refuge in a fenced-in maintenance area, which is the rats' nest. They discover cutting torches and drums of flammable liquids and soon, the three escape from the tunnel as the rats are killed during a flammable explosion behind him. After the three survivors re-board the subway train to reach safety, the train reaches the platform and the party-goers for the new subway section approach the train and to their shock, it is revealed that the three had boarded the same train as Mayor Rizetti did, which shows a small amount of surviving rats eating the body of the mayor, as the final scene shows a bloody rat hissing at the train window.
s wearing rat suits were used in the filming of Deadly Eyes to achieve the effect of super-sized rodents. However, during filming, one of the Dachshunds playing the rats died on set, possibly due to suffocation from being trapped in the rat suit. Although the dogs were generally treated well during production, this was an exception. James Herbert, who wrote the novel upon which the film was based, was displeased with what the filmmakers did to his story, and described it as "terrible... absolute rubbish."
