"Well... We were mixing it up inside the Shredder's ultimate weapon - The Technodrome. Trying to keep him from getting his claws onto some vials of Mutagen. We were looking for a way to end the fight once and for all. When Don had a rockin' idea. Use the Technodrome's own Trans-Dimensional Portal to send it back from whence it came. Don started working his Techno magic, but... The next thing we knew, we were back in the city."