For centuries, the Mapmakers kept peace in the Valley, but they've long since disappeared. One night, on the run from the Night Coats, Alidade stumbles upon a secret door leading to a magical hideaway that belongs to the Mapmakers. There, she finds a map of her home, and accidentally brings to life Blue, a magical creature called a Memri who is meant to protect the Valley. Blue needs Alidade's help to find the Mapmakers and save the Valley from the Night Coats! But the Mapmakers are long gone. Alidade has a choice - leave the Valley like she's always wanted or become a Mapmaker and save the only home she's ever known.