In the town of Napville, policeman Officer Buckle frequently gives safety speeches at the local school, but the boring nature of his speeches causes the students to lose interest. One day, Officer Buckle is assigned to take a police dog named Gloria to the school for a safety speech. During the speech, Gloria, behind Buckle's back, demonstrates the safety tips discussed by acting out the effects in pantomime. The speech is a success as Gloria's performance catches the students' interests, and a confused but thrilled Buckle receives a vast number of letters from the students, unaware that their attention is focused on Gloria and not him.
As time passes, Buckle gains fame as he gives safety speeches to other schools with Gloria. He does not realize the truth behind his fame until he sees a taped speech of his at a college, revealing Gloria's antics. Livid, Buckle refuses to give a planned speech at the local school, so Gloria is brought to the school by herself. Without Buckle, Gloria becomes lonely and falls asleep, ending her stay early; afterwards, a large accident happens at the school as a spilled jar of banana pudding causes students to slip into the principal, who accidentally hurls a hammer towards the crowd upon impact.
The next day, Officer Buckle is horrified when he receives another stack of letters from the students, detailing the accident; upon seeing a letter from a student named Claire, who notes how Gloria had missed him the day before Officer Buckle reconciles with Gloria and decides to return to giving safety speeches. In the end, Officer Buckle and Gloria go to many schools and teach the students about safety together.