In a misguided effort to improve the village of Hamelin and boost its prestige in the eyes the king, the mayor (Claude Rains) sentences all citizens, including children, to work on civic improvements. When a rat problem threatens to undermine his efforts, the mayor hires a traveling piper (Van Johnson) who claims he can charm rodents. But as the overworked local children meet the charismatic piper -- who delights them with his magical powers -- they too fall under his spell.