Po is gearing up to become the spiritual leader of his Valley of Peace, but also needs someone to take his place as Dragon Warrior. As such, he will train a new kung fu practitioner for the spot and will encounter a villain called the Chameleon who conjures villains from the past.
The Avengers gather to celebrate their latest victory, but their celebration is quickly interrupted by the mysterious disappearance of Black Widow's father, Red Guardian. As the Avengers investigate, they discover that Red Guardian isn't the only one missing when they meet a dangerous new foe quite unlike anything they've ever encountered before.
Continuing his "legendary adventures of awesomeness", Po must face two hugely epic, but different threats: one supernatural and the other a little closer to his home.
Two boys face an onslaught from witches, monsters, ghouls and a talking dummy after they discover a mysterious book by author R. L. Stine.