In their underground lair deep beneath the city streets, the Turtles and Master Splinter are suddenly attacked by a horde of Mouser robots!

Raphael is a little cooped up underground with only his brothers and Master Splinter. When Raphael almost clobbers Michelangelo in some brotherly sparring, it's apparent that Raphael needs to get out ... let off a little steam. But when he meets up with Casey Jones, a vigilante erring a little to the right of justice, Raphael must face the reality of his own hothead ways...

With all the turtles living in April's apartment, things are getting a little crazy. But, when Donatello stumbles upon a fantastic monster in the basement, things get crazier.

The Battle Nexus Tournament nears it's conclusion : Dontello finds himself fighting for his life with Usagi Yujumbo as Mikey is poised to become Battle Nexus Champion. Leonardo's condition worsens, and Splinter is still in prison. Worse still, Lord Draco now has control of the Daimyo Warstaff...

After the Turtles were able to cure Donatello's mutation, a group of ninjas confronts the Turtles to tell them about a battle between good and evil that will decide the fate of the world.