New World Order (1) (S05E07)

The Foot Mystics bring back the original Shredder, whose first mission is to eliminate Karai, the so-called “false Shredder.” Although the Turtles find themselves at odds with both Shredders, they come to understand that if the original succeeds, his vision of a world filled with chaos and ruin will be perilously close to fruition. Reluctantly, they must aid Karai in her efforts, even as she remains determined to destroy them!