The frost is coming. The whole village must go down.
The Flatlings are thumb-sized hood-folk who live in the crown of the Old Tree. Snow is creeping down. The whole village must walk down through Mosswood, Stonewell and Emberdeep to the Warm Hollow at the mountain's heart, and in spring, through Skyward, all the way back up to the open sky. You are Glim, the Keeper's firefly.
They walk and never stop to think. A Flatling turns only when it bumps into something, and it falls off every edge it meets; fall too far and it lands flat, in a puff of leaves. So you read the whole cut through the mountain, plan a way down, and hand out jobs: dig here, glide there, a stair over the river, a stopper before the cliff. One good job saves the lot.