After being provoked from stopping the Kraang invasion and being outmatched by Shredder and Kraang Prime, April, Casey and the Turtles take refuge inside a cabin far from the city in the woods.
After 3 months of being in a coma,Leo finally wakes up. Raph tries to train him back to normal, but Donnies medicine makes Leo too sick. Leo drops the medicine and creates a monster who hunts and changes everyone down, but they defeat them, with Leo's weak health.