A young aspiring engineer must first conquer her fear of failure.

Young Violet's only friend is her dog, Orville, until one of her homemade flying machines takes her to the rescue of a Boy Scout troop in trouble.

Christopher is 'Proper': a real boy with a real soul, orphaned in a fire. He works for an engineer, a maker of the eccentric, loyal and totally individual mechanicals who are Christopher's best friends. But after a devastating accident, a secret is revealed and Christopher's world is changed for ever...What follows is a remarkable adventure, as Christopher discovers who he really is, and what it means to be human.