When farm boy Homer Pudding's explorer-uncle dies and leaves him a droopy dog with a mysterious coin hidden on its collar, it leads him to The City, where they meet Madame La Directeur, the conniving head of the Natural History Museum, who is trying to steal the coin and take Homer's place in a secret society of adventurers.

Fourteen-year-old Brystal Evergreen has secured worldwide acceptance for the magical community but new threats arise, including the centuries-old Righteous Brotherhood that intends to exterminate all magical life, beginning with Brystal.

Archie Dent and his friends Hachi and Fergus, the first three members of a new League of Seven, a group of heroes who come together to fight the Mangleborn whenever the monsters arise to destroy humanity, undertake separate missions and in the course of their adventures meet potential candidates to join their League, while learning deep-rooted secrets that could destroy the League forever.