Intellectual teenager Marcy Wu left Amphibia behind to embrace the new changes in her life. No more running, no more fantasies, just her life and the reality that comes with it. But things change for her once again when a series of events leads to mythical creatures being summoned from another world and start terrorizing the streets of Los Angeles. What could possibly go wrong?

(Sequel to Marcy and the Black Knight) A month following their escape from Newtopia, fate sends Marcy Wu and her new partner Toothless on a dangerous quest across Amphibia to seek a hidden relic that holds the key to their destinies. Throughout their journey, they will encounter new enemies, and meet new friends that will help them in their fight that will change the world forever.