The turtles and Splinter have taken a little trip down the Utroms' memory lane via a high-tech virtual reality device experiencing first hand the Utroms' crash landing on Earth and their life in feudal Japan.
The Turtles return to the ancient underground city they discovered in "Notes From the Underground", only to find the city abandoned, its crystal moon power source missing, and its human population reverted to monsters.
The turtles have their hands full fighting the mob, the Purple Dragons and what's left of the Foot. Now, they've joined forces with Karai, who used to be the Shredder's right hand "man." Can they trust her?
Now that they've got a ShellSub, the Hudson River becomes the Turtle's underwater wonderland... NOT!The junk in the riverbed is even more dangerous than the city above when the Turtles run into their old nemesis the GarbageMan.