The Turtles are watching a cheesy old sci-fi movie, Invasion of the Space Turtles, which reminds them of Kerma and the Turtleoids. They begin to worry that someone might be menacing the Turtleoids, and decide to go to Channel 6 in an attempt to contact Kerma.
On the Technodrome, the villains are experiencing power fluctuations, so Krang decides that they can use a solar storm for their own ends. He plans to use the Colossus Building to make a solar collector that can repower the Technodrome. Since the Turtles are sure to interfere, he also has deadly Hunter Drones ready to attack.
The Turtles are surprised when Kerma's spaceship arrives right near Channel 6, and Kerma reveals that he needs their help once again. They blast off with Kerma, just as the Hunter Drones break into Channel 6 and start wrecking the place. They continue searching for the Turtles, and eventually conclude that they no longer exist.
Kerma reveals that his latest problem is that he has constructed defense robots for the Turtleoids, but they aren't functioning properly. In particular, they're timid and non-aggressive, because their maker doesn't understand aggression. While Donatello is reprogramming them, Groundchuck and Dirtbag return to steal the gold machine, along with the cyborg brigand Captain Dredd. The Turtles are able to defeat them easily in a fight, but they grab Kerma and fly off. After being tormented by his captors, Kerma becomes infuriated enough to break his bonds.
Donatello, meanwhile, jerry-rigs a forcefield generator to cover the gold machine. Just then Kerma flies back to Shell-ri-la with Groundchuck and Dirtbag's ship, and Leonardo suspects that he's finally ready to learn to defend himself. However, martial-arts practice with Leonardo shows that Kerma has a long way to go.
Back on Earth, Krang and Shredder make their way to New York and head for the Colossus building. Once they arrive, a giant cable is brought to connect the rooftop to the Technodrome.
Groundchuck, Dirtbag and Dredd all return to Shell-ri-la, and this time they brought a team of bulky aliens called the Brute Force. These opponents are harder for the Turtles to deal with, but just then Donatello brings out Kerma's reprogrammed robots. Unfortunately, they are hyper-aggressive now, and immediately turn on the Turtles until Donatello can get them back under control.
Groundchuck, Dirtbag and Dredd begin ransacking the Turtleoid city, and Donatello uses the robots against them... only for their soft gold bodies to be easily wrecked. This is the last straw for Kerma, who begins lashing out at his enemies with newfound aggression. Brute Force are driven back onto their spaceship and off the planet, while Groundchuck and Dirtbag are subdued by the Turtles. Dredd is more difficult because of his cyborg enhancements, but Donatello is able to reprogram his robotic body and make him tear himself apart.
The solar energy is pouring into the Technodrome when Kerma's ship returns to Earth, and the Turtles notice what's going on. Donatello asks Kerma to blast the cable, which causes massive feedback in the Technodrome. Their control room is badly damaged.
The Turtles say goodbye to Kerma, noting that now he can teach the other Turtleoids how to defend themselves. The Turtles sit down to watch the old B-movie once again, but become uneasy when the movie has a line about the turtle aliens being peaceful until they learned about war. Leonardo begins to worry that they've done the wrong thing by teaching Kerma about aggression, but Michelangelo firmly assures them that "it's the END."
- Leonardo (Cam Clarke)
- Donatello (Barry Gordon)
- Michelangelo (Townsend Coleman)
- Raphael (Rob Paulsen)
- Splinter (Peter Renaday)
- April O'Neil (Renae Jacobs)
- Irma Langinstein (Jennifer Darling)
- Burne Thompson (Pat Fraley)
- Vernon Fenwick (Peter Renaday)
- Shredder (Townsend Coleman)
- Krang (Pat Fraley)
- Bebop (Barry Gordon)
- Rocksteady (Cam Clarke)
- Dirtbag (Pat Fraley)
- Groundchuck (Bob Ridgley)
- Captain Dredd (Lloyd Sherr) (Debut)
- Kerma (Jan Rabson)
- First Hunter Drone (Townsend Coleman) (Debut)
- Second Hunter Drone (Peter Renaday) (Debut)
- Turtles' Lair
- Shell-Ri-La City
- Channel 6
- New York Harbour
- The Smash Up Bar asteroid
- Shell-Ri La sewer system
Home media releases
- Teenage Mutant Ninja Turtles Season 7
- Teenage Mutant Ninja Turtles: The Complete Classic Series Collection
- After Captain Dredd kidnapps Kerma, Raphael's "R" is colored white.
- The close-up shot of Krang in his bubble walker after Shredder's sword has been broken is colored yellow.
- Raphael mentions the time Groundchuck and Dirtbag destroyed Shell-Ri-La city's force dome but doesn't mention Dirtbag's part in it.
- Leonardo's sword doesn't make a sound when Captain Dredd breaks it with his energy blade.
- When Leonardo is battling Dredd he's seen with one sword on his belt, but it disappears after his other one breaks.
- When Captain Dredd's first ship arrives in Shell-Ri La City, the ship is seen in another shot behind the Turtles as they're running towards them.
- When Krang says that the Technodrome is running dangerously low on energy, the animation cell for the control panel that he is typing on moves slightly.
- All of the Turtles' leg bands are colored blue when they exit the Channel 6 building to greet Kerma.
- In the close-up shot of one of the Hunter Drones at the Channel 6 building before the commercial break, the Drone's head suddenly becomes bigger.
- Krang's robot hands are flesh colored instead of the usual red when the Hunter Drones tell him that the Turtles have been destroyed.
- Raphael unties one of his wristbands when fighting Groundchuck and uses it to make him charge into a wall, but the wristband is clearly still tied to his wrist and the "wristband" he removes is far bigger when unfolded than it should be.
- Kerma's teeth are coloured red after he complains about the turtle robots being destroyed by the Brute Force troops.
- Dirtbag's eye is coloured white instead of yellow when he lands on the ground after pulling Michelangelo and Raphael into the hole.
- Leonardo emerges from the hole when only Michelangelo and Raphael are seen being pulled into the hole.
- When Kerma describes Captain Dredd to the Turtles, the blade on Raphael's left sai is missing.
- Michelangelo: Come on steak-face, hit me with your best shot!
- Groundchuck: Hey, don't you make fun o' my prize-winning good looks, boy!
- Captain Dredd: (to Donatello) Do you want to be destroyed along with your friend?
- Donatello: No. I want you to drop that sword! (he presses some buttons on the gold Turtle remote, which causes Captain Dredd to lose control over his body)
- Captain Dredd: Wha?.. What the...I can't control myself!
- Donatello: Oh, don't be so hard on yourself!
- Captrain Dredd: (destroying himself) No!, No!, Noo! No. You can't do this to me! (laying in a pile) I am the great Captain...Dreeeeedd!
- Michelangelo: Face it dude, from now on your the great "Captain Mud!"
- Raphael: Let's get these creeps locked up so we can go home!