É uma série de livros intitulada " The Grey Griffins " publicado pela primeira vez em 2006. O primeiro romance foi "Revenge of the Shadow King".
The Grey Griffins series follows the story of four sixth graders who live in the fictional city of Avalon, Minnesota. These four friends formed a secret order named The Order of the Grey Griffins, consisting of, Grayson Maximillian "Max" Sumner III (the leader) and his friends: Natalia Romanov (the marshal), Ernie Tweeny (the steward), and Harley Eisenstein (the warden). In The Revenge of the Shadow King, the Grey Griffins discover a link between their 'innocent' card game (Round Table) and a magic book (the Codex Spiritus) which Max discovers in his grandmother's attic.
Portanto, a cidade é fictícia, no entanto, existe uma companhia de seguros de vida real chamada "Avalon Insurance".