Above, in the cloudlands, Nimh has no memory of her past, only an aching, undying certainty that she has left something, someone, behind. But while she struggles to recall her identity, an imposter wields her name with deadly purpose. Below, on the surface, North looks to the sky, desperate to join the person he loves and return to his world. But with only a traitor willing to help him, and others clamoring for him to take Nimh's place, his home seems more unreachable than ever. Tragedy looms as the cloudland engines falter and mist rains terror on the surface, and in their desperation to reunite and save their people, Nimh and North face one ultimate question: can they defy their love and their destiny to save their homes? Or will the spark between them ignite their worlds, and consume them all together?