When Aninku and Pepicek go to town for milk to make their sick mother better, their attempts to earn money by singing are thwarted by a bullying hurdy-gurdy grinder, Brundibar. But with the help of three talking animals and three hundred schoolchildren, Aninku and Pepicek defeat the bully and return home triumphant. The story is based on a Czech opera performed numerous times by the children of the Nazi concentration camp Terezin.