As the TMNT continue to train under the tutelage of the Shredder in Northampton, the techniques they are learning take a bizarrely arcane turn. Will Michelangelo, Donatello, Raphael, Leonardo, and Jennika learn how to master and control the dark ninja arts... or will they be consumed by them? One thing's for certain: if they are to have any chance at success, they will need to seek out a light from the past to help guide their way.