In a medieval yet futuristic world, Clay, Aaron, Lance, Princess Macy, and Axl are five young knights who protect the kingdom of Knighton and it's capital Knightonia from Jestro, the Book of Monsters, and their army of Lava Monsters. They also receive help from the Knightonia Royal Family, the digital wizard Merlok 2.0, Robin Underwood, and Ava Prentiss. In season 3, the Cloud of Monstrox appears following his defeat as the Book of Monsters as he once again controls Jestro into helping him obtain the 10 Forbidden Powers where the Cloud of Monstrox uses his evil lightning to animate his Stone Monsters. The two of them later ally with a sculptor named Roberto Arnoldi who helps to sculpt things out of rock for Jestro and Monstrox to use.
