Celestine is a little mouse trying to avoid a dental career; Ernest is a big bear craving an artistic outlet. When Celestine meets Ernest, they overcome their natural enmity by forging a life of crime together.

Ernest and Celestine are travelling back to Ernest’s country, Gibberitia, to fix his broken violin. This exotic land is home to the best musicians on earth and music constantly fills the air with joy. However, upon arriving, our two heroes discover that all forms of music have been banned for many years – and for them, a life without music is unthinkable. Along with their friends and a mysterious masked outlaw, Ernest and Celestine must try their best to bring music and happiness back to the land of bears.