The Revenge of the Shadow King (Grey Griffins #1)

In this captivating debut novel, four friends—Max, Harley, Ernie, and Natalia—discover that the fantastical creatures from their beloved card game have come to life, wreaking havoc in their quiet Minnesota town. As members of the secret club The Grey Griffins, they are among the few who notice the bizarre occurrences around them. Realizing the danger posed by goblins, fairies, and unicorns, it's up to the friends to confront these wicked forces and protect their home from impending chaos.