In the magnificent city of Aeridor, which floats serenely on an ocean of clouds, life is bathed in the golden light of the magical Sun-Gem. But when the light is suddenly stolen by the grumpy Baron Von Gloom, the city is plunged into a cold, unending twilight, and despair descends with the darkness.

The city's only hope lies with an unlikely pair of heroes: Pip, a brilliant, goggle-eyed gadgeteer whose workshop buzzes with half-finished inventions, and Elara, a quiet girl who possesses the remarkable ability to speak with birds. Together, they hatch an audacious plan to steal back their stolen sun.

Armed with Pip’s clockwork wings, a pair of sticky-soled shoes, and a secret blueprint drawn on a kite's tail, they embark on a perilous journey to the Baron's jagged fortress, Castle Cumulus. They must navigate the sorrowful Weeping Winds, outsmart silent clockwork owl patrols, and survive a labyrinth of lightning rods. But when they finally reach the heart of the castle, they discover that the Baron has stolen more than just their light, forcing them to make a choice that could change the sky forever.

Can a boy's wild inventions and a girl's unique friendship with the creatures of the sky be enough to pull off the most daring heist imaginable and bring the dawn back to Aeridor?