The legendary Elfkins (Heinzelmännchen) of Cologne were gnomes secretly helping craftsmen at night until they were ousted by a tailor's malevolent wife 200 years ago. This is the story of their return.

Helvi's world is turned upside down when she discovers the existence of a technically advanced Elfkin gang that, in stark contrast to Elfie’s own clan, is second to none when it comes to fun and thrill-seeking. Can Helvi’s friendship with Bo, the youngest gang member, reconcile the two Elfkin clans after more than 250 years?