The Turtles and Rainbooms are back again, this time teaming up with Mystery Inc.

When the gang stops in New York to visit Fred's cousins, they cross paths with the Turtles and Rainbooms and also stumble upon another mystery, involving a ghost. But the ghost is someone from the ninjas' past: Ho Chan! Now, the two teams must work together in order to solve the mystery and defeat the ghost before he unleashes chaos throughout the city.