On Halloween night, a little ghost went treat-or-treating and lost his mom. For Gaspard, disguised under a sheet, it's the beginning of a sleepless night. His adventure leads him from the city to the forest and heightens his senses. Whilst the sunset enhances the landscape and stops the wild animals' race, the beauty takes over his worries about the upcoming night. On his own, Gaspard reveals himself little by little. At dawn, he hears a familiar voice: what a joy for Gaspard, who's not really the same anymore: he grew up.