After supervillain Shredder escapes custody, he joins forces with mad scientist Baxter Stockman and 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 evil with similar intentions: the notorious Krang.

Marcel is an adorable one-inch-tall shell who ekes out a colorful existence with his grandmother Connie and their pet lint, Alan. Once part of a sprawling community of shells, they now live alone as the sole survivors of a mysterious tragedy. When a documentarian discovers them amongst the clutter of his Airbnb, his resulting short film brings Marcel millions of passionate fans, as well as unprecedented dangers and a new hope at finding his long-lost family.