Episode Title:The Invasion Part 1 & Part 2.Episode Description:The Invasion Part 1: As a last resort at getting back at the Turtles and Splinter for Karai's mutation, Shredder and the Kraang join forces as the Kraang launch a full-scale Invasion on Earth. With the Kraang now attacking New York, Leo and Donnie argue over strategies for defeating the Kraang.
The Invasion Part 1: With their home destroyed by Irma, who was revealed to be the Kraang's second-in-command, Kraang Sub-prime, in disguise, and the mutagen greatly perfected, the Turtles, April, and Casey must survive the ongoing assault of the Kraang Invasion, while Leo goes head-to-head with Shredder's men and his army of foot-soldiers. Meanwhile, Splinter and Leatherhead go one-on-one with the Shredder himself.