An out-of-the-ordinary encounter with strange alien ooze mutates four ordinary pet turtles - Leonardo, Raphael, Michelangelo, and Donatello - into talking, walking, fighting green machines! Together, these brothers train with the legendary sensei rat, Splinter, to master the martial art of Ninjitsu. In this truly turtle-powered tale, the turtles from one dimension meet the turtles from another dimension when a teleporting mishap occurs. What the shell is going on? Together, the turtles must locate the Technodrome to fix this mess! Meanwhile, Shredder tracks down his counterpart, Ch'rell, who devises a master plan to travel back to the Prime Universe to get rid of the turtles once and for all! As worlds collide, the turtles come face-to-face with classic characters like Casey and April, and a slew of enemies including Krang, Hun, the Foot Soldiers, the Purple Dragons, Bebop and Rocksteady!