Michelangelo, Donatello, Leonardo, and Raphael are back to battle bigger, badder villains, alongside April O’Neil and a newcomer: the hockey-masked ally Casey Jones. After supervillain Shredder escapes custody, he joins forces with two dimwitted henchmen, Bebop and Rocksteady, to unleash a diabolical plan to take over the world. As the Turtles prepare to take on Shredder and his new crew, they find themselves facing an even greater threat with similar intentions: the notorious Krang.