Cody tries to send the Turtles back to their own time, but he can't recreate the accident that transported them to 2105 in the first place. In order to get parts for his time window, Cody and the Turtles take a trip to O'Neil Tech, the corporation that April and Casey founded, and Cody is now the owner of. But whilst there Cody is kidnapped by four strange creatures, and the Turtles must rush to his rescue.
First appearance of Darius Dun, Starlee Hambrath and the Inuwashi Gunjin
This episode provides examples of:
- Awesome, but Impractical: Mikey's Powered Armor looks cool, but it's unwieldy and falls apart in battle.
- Catch a Falling Star: Raph uses his hover vehicle to catch Cody when the boy is knocked off a skyscraper
- Comically Missing the Point: When Serling mentions that the Turtles' destruction of Cody's living room is a disaster after Splinter knocks Mikey down with a rolling pin, Master Splinter replies:Splinter: Yes; Michelangelo should have seen that coming.
- Face Palm: Raph pulls a few through the episode.
- Gratuitous Japanese: The Inuwashi Gunjin, named so despite the fact that they have no apparent connection to Japan besides the name. (It actually means Golden Eagle Soldiers.)
- His Name Is...: Just before the Inuwashi Gunjin can reveal who sent them after Cody, Darius remotely puts them into stasis.
- Last of Their Kind: The Inuwashi Gunjin.
- Mistreatment-Induced Betrayal: The Inuwashi Gunjin do not like being under Darius Dunn's thumb, and decide to hold Cody hostage in exchange for their freedom.
- Powered Armor: the 'Mikeytron 6000'.
- Properly Paranoid: Leo and Raph note how convenient it was that Darius showed up just after the Inuwashi Gunjin were defeated, but just before they started talking. They intend to keep an eye on him.
- Proud Warrior Race: The Inuwashi Gunjin.
- Reality Warper: The Transcendental Lathe at O'Neil Tech, which creates physical objects from the user's thoughts.
- Shout-Out: Mikey calls one of the Winged Humanoid Inuwashi Gunjin "Tweety".
- Title Drop: The word "obsolete" is spoken through the episode, which refers to the Inuwashi Gunjin.
