The Darling Undesirables takes place in a post steampunk world where dark matter and dark energy have been harnessed by a reclusive genius known as "Father Inventor" – revered by many, reviled by more.

Energy problems solved, humanity is obsessed with unlocking the secrets to eternal life. Unrestricted experimentation has produced a population of parentless and deformed children, the Darling Undesirables.

Named for their missing body part, each Darling Undesirable is pampered and indulged. The most adored Darling Undesirable, 15-year-old Heart, dreams of escaping with her friend, Eye, and the beloved, centuries-old, clockwork horse.

But first, she must save Father Inventor and the world he brought into being from the evil forces of The Purists.