Shredder attempts to use the world trade center in an experiment, but the failure of Baxter's essential new device, plus the interference of those heroes in a half shell, prevent the villain's plot from succeeding. Frustrated at Baxter's latest failure, Shredder contacts Krang in Dimension X and demands that Rocksteady and Bebop be sent to aid him.
Krang informs shredder that an exchange must be made to enable the portal to open properly, Shredder has the perfect candidate to take Rocksteady and Bepop's place: BAXTER!
So, with a quick gesture (literally, Shredder actually throws Baxter into the portal), the transfer is made, and Shredder gets his old henchmen back.
Baxter's fate, sadly, is not so pleasant, Krang immediately orders his execution, and he is sent to the disintegration chamber. A tiny Fly is his sole company inside the chamber as the device is activated. But fate has other ideas for the scientist.