When their parents disappear in the middle of the night, young sisters Summer and Bird set off on a quest to find them. A cryptic picture message from their mother leads them to a familiar gate in the woods, but comfortable sights quickly give way to a new world entirely--Down--one inhabited by talking birds and the evil Puppeteer queen. Summer and Bird are quickly separated, and their divided hearts lead them each in a very different direction in the quest to find their parents, vanquish the Puppeteer, lead the birds back to their Green Home, and discover the identity of the true bird queen.