Hokum Hare discovers that Shredder has a 'time train' to travel to the future, where he can become a crimelord of a crime-free era. The Turtles and Hokum grab a ride on the train, arrive in the future to find the elder versions of the Turtles, now retired! Shredder plans to kick older Turtle butt, and the younger Turtles try to whip their older selves into shape before the big confrontation. (thetvdb.com)