chunk: The Generals intend to substitute Leo for the thirteenth missing beast and Raphael decides to make amends for his past mistakes by rescuing Leo. As the portal opens, Yaotl discovers his Generals' treachery, while Splinter and the Turtles, accompanied by Casey and April, fight their way through the Foot Clan cordon and breach the tower. Yaotl reveals the truth to the heroes: he wants to be free of his curse of immortality. The Generals reveal that they wish to preserve their immortality, but also to use the portal to bring in more monsters to conquer the world.