During a night patrol across New York's rooftops, the four Turtles are ambushed by Foot Soldiers. With April's help they uncover the reason: the Foot Clan has constructed a Mutagen bomb with enough power to transform the entire city. After defusing the bomb, the Turtles receive a call from April's hijacked phone—Shredder himself, with a demand. He has taken April captive and will release her only if the Turtles deliver their master Splinter to him.