The Challenge of Samukai!

"Sensei Wu has trained Cole, Zane, Jay, and Kai to be Masters of Spinjitzu, and together they defend the world of Ninjago from the dark forces of the Underworld. But when Samukai boasts that he can defeat Sens[e]i Wu and his four young ninja, Garmadon takes him up on his bet!"--Page 4 of cover.