Usagi and Gen come to New York for a visit with the Turtles. Gen gets a little carried away by the bright lights of the big city and goes wandering off on his own. And if the modern world wasn't dangerous enough, an assassin from Usagi's world has followed Usagi and Gen. His target: Leonardo.

While Leonardo is in Japan studying with the Ancient One, Karai as the new Shredder makes her attack. Will Leo return to New York? Will he find out what happened to his home and his family? And, have Splinter and Turtles really been destroyed?