Nano

In a high-tech laboratory, Dr. Marion Richards conducted an experiment in nanotechnology for the U.S. government. Her nanobots were able to dissemble household appliances and create a robotic appearance for themselves. Dissappointed by the nanobots' tendency to copy humans, she zapped it to make it lose it's shape and left the lab. The nanobots' took that opportunity to escape the lab.

In the city, the nanobots ran into a man selling toy robots. The man was Harry the Pickpocket. He stole a customer's wallet and ran into an alley. While running, he slipped on the nanobots and fell. All of his toy robots broke as he fell and the nanobots used them to create a body for themselves. The Nanobot thought of Harry as their father. Harry decided to use them to add his crimes. He robbed several shops near April's 2nd Time Around.

April became worried about the break-ins and asked the turtles to spend the night at her shop. That night, Harry and Nanobot did attempt to break in. The turtles fought the two, who made a quick retreat. However, Donatello managed to get a piece of the nanobots. Don studied the piece to discover exactly what it is. He also found out that they are vulnerable to heat.

The turtles decided they had to stop the Nanobot before it got too big. Don developed a tracking device that let the turtles find the Nanobot in the junkyard. They arrived in the Battle Shell. As they fought, the Nanobot kept grabbing junk to make itself bigger. Through teamwork, the turtles managed to trap the Nanobot with an electromagnet. Harry tried to save the Nanobot by cutting off the magnets power, but when he does, the Nanobot falls into a blast furnace. Harry realizes that he made a mistake in using the innocent Nanobot.