The Guardians of Arcadia reunite to battle the nefarious Arcane Order, who’ve reawakened the primordial Titans.

Douxie, Claire, Steve and Jim meet the legendary King Arthur and his sister, Morgana, in medieval Camelot — where being a troll is punishable by death.

Morgana takes a new title — Mother of Monsters — and vows to usher in an age of reckoning. An epic battle begins in King Arthur’s court.

After returning to the 21st century, Jim makes a surprising sacrifice … and a familiar face joins the fight. The Green Knight finally reveals himself.