Splinter suffers amnesia as the Turtles try to remind him that he is the true leader of the Foot Clan.

It's Michelangelo's birthday, but none of his brothers seem to remember, and it frustrates him greatly. Meanwhile, Shredder and Krang discover what is possibly an "anti-mutagen" that, after testing it on three rock soldiers, can undo mutations. Shredder, Bebop and Rocksteady are sent to use it on the Turtles, and our heroes have a few close calls.