When a plague of rats infests the city and the sewers, the Turtles find themselves having to deal with a new threat: The Rat King.
Tropes
- Blame Game: Vernon tries to blame Irma for April's sudden disappearance. When she interrogates on why, he can't come up with a reason. Not even a bad one.
- Brainwashed and Crazy: The Rat King's flute allows him to mentally control rats. Since Master Splinter is a rat himself, he too falls under the Rat King's control.
- Breaking the Fourth Wall: When the turtles scale the Channel 6 building, Donnie openly laments that they don't have the gravity boots from episode 6.
- Fighting from the Inside: Splinter manages to free himself from the Rat King's mind control by resisting his order to finish off the Turtles.
- Nice Job Breaking It, Hero: April accidentally outs the turtle's ninja master as a rat, giving the Rat King the idea of turning him into his minion and using him to fight the turtles.
- Present Company Excluded: April uses this when she complains that every rat should be chased out of town in front of Master Splinter.
