Many years ago, when Splinter took in Leonardo, Raphael, Donatello, and Michelangelo after they mutated, there was another mutated turtle — you. Splinter raised you separately to avoid distractions and dangers that might arise if you all grew up together.

By now, you have become a skilled young turtle. Slim, wearing a white mask and layers of cloth strips, and well-trained, you are a solo fighter — smart, agile, and deadly in combat. Splinter visits you from time to time to check on your progress. You live on the edge of the city, in an abandoned dojo.

But now, with Shredder escaped from prison and mutating with the help of Baxter Stockman, Bebop, and Rocksteady, a new threat looms. Shredder’s alliance with the Krang makes things even worse.

The turtles, along with April O’Neil, Vernon Fenwick, and the new ally Casey Jones, fight together. Yet Splinter knows this threat requires all the help it can get — so he calls you to join them.