With the demise of their beloved father and Karai incapacitated, the turtles, April, and Casey infiltrate Super Shredder's new lair to put an end to Oroku Saki once and for all, no matter what it takes.
Super Shredder has returned with even greater vengeance, forcing the Turtles to enlist the combined aid of Splinter, April, Casey, Karai, Shinigami and the Mighty Mutanimals to destroy him once and for all.
Leo and Donnie disagree about their plan to stop the Kraang invasion. When Leo makes a critical mistake, he is separated from the team and Donnie must step up as a leader.
Facing Shredder's deadly new assassin, Leo must decide whether to risk his brother's lives or ask for Splinter's help. Donnie must put aside his rivalry with Casey in order to uncover a new Kraang plot.
Leonardo considers asking Splinter for help while facing Shredder's new assassin; Donnie must put aside his rivalry with Casey in order to uncover a Kraang plot.