Hazel’s parents take her to her grandmother’s village, where she is initially disappointed by the lack of internet. Used to spending all her time on her phone, Hazel is frustrated until she climbs out onto the roof of an old shed on the Bare Hill hoping to "catch a signal." She stumbles and falls in, where she meets a wood spirit called Grunewald, who introduces her to the Deep Woods —a place inhabited by mythical creatures and talking animals.

The shed turns out to be a Lost and Found Bureau," where magical items lost in the forest are collected. Excited by the adventure, Hazel decides to help Grunewald return these lost items to their owners. To be lost and forgotten is unfair, so Hazel wholeheartedly wants to help the lost to be found… only to discover something more important in the process.