Metalhead Rewired

Metalhead Rewired is the thirty-seventh episode of the series. It aired on Febuary 23, 2014.

Major Characters

 * Donatello (Rob Paulsen)
 * Leonardo (Jason Biggs)
 * Metalhead
 * Michelangelo (Greg Cipes)
 * Raphael (Sean Astin)

Minor Characters

 * Dr. Tyler Rockwell (Frank Welker)
 * Kirby O'Neil
 * Justin
 * Parasitica Wasp
 * Pete
 * Slash (Corey Feldman)
 * Snakeweed
 * Spider Bytez (Lewis Black)
 * Splinter (Hoon Lee)
 * Spy-Roach
 * Squirrelanoid
 * Newtralizer

Plot Synopsis
The episode opens up with Metalhead's point of view, observing the four Turtles. Donatello then reveals to his brothers that he has vastly upgraded Metalhead's A.I. in order for him to effectively work alongside the Turtles (and listen to their every command as well). Donnie has also apparently programmed him with multiple fighting styles, some of which he was able to simulate from both the Foot Clan and the Kraang, for instance. After a brief training session, Metalhead's upgrades (and fighting skills) are noted to be VERY effective and inimitable - after the robot easily prevails against all four of the brothers at once in combat, much to even Master Splinter's surprise....who also tells Donnie that he must use his creation wisely (and not allow it to go over the top and become hostile towards the other Turtles).

When one of the security wires is randomly tripped outside and sets off Metalhead's vocal alarm, the Turtles set out to check who is near the entrance to their lair, only to discover a frenzied Spider Bytez being chased down by three Kraang droids there. Despite Spider Bytez pleading for the Turtles to possibly save him, he is captured by the Kraang on the surface before he can explain at all what happened...Thanks to Donatello, Metalhead is already prepared for taking action and he quickly arrives with the Shellraiser (using his degree of independence granted to him) in order to chase down the Kraang's truck. After a lengthy battle on the road with the Kraang's vehicle, Metalhead manages to crash the Kraang's getaway. However, when the Turtles get out to investigate, they realize that the vehicle and Spider Bytez have both disappeared inside of a parking gargage. While investigating the crash site for clues, Leonardo begins to show what seem to be signs of jealously towards Metalhead's new usefulness. When Michelangelo accidentally stumbles upon what seems to be a Kraang computer behind a nearby vending machine, Donnie orders Metalhead to try and gain access into it to find any sort of potentially useful info, only to wind up destroying it entirely and harming himself, giving him the scorn of the other turtles...

Back at the lair, Donatello diagnoses Metalhead's condition and states that he can be fully repaired after "a while". Metalhead's lengthy repairs however begin to eat away at the other turtles's patience, until Leonardo finally orders Donatello to shut down Metalhead's A.I., informing Donatetllo that Metalhead is just too dangerous and unpredictable to use. Metalhead, however, overhears Leonardo's conversation and, unwilling to be shut down, it locks all of the Turtles inside Donatello's lab and rapidly leaves somewhere. After being set free by Splinter, the Turtles quickly set off in the Shellraiser to find Metalhead, under the impression that it has gone rogue. Upon finding the robot, Metalhead steps into a Port-a-potty and disappears into it, much to the Turtles' utter confusion. To their luck, Michelangelo is somehow able to reveal that the port-a-potty actually has what appears to be a portal inside of it, which proceeds to suck them all into it...

Inside the portal, the Turtles discover that it leads to a secluded base that belongs to The Kraang. The base also acts as a prison to every single one of the mutants that had faced the Turtles in the past, all of which include; Snakeweed, Spider Bytez, Dr. Tyler Rockwell's mutated form, Pete, Justin, Spy-Roach, The Parasitic Wasps, Kirby O'Neil's mutant form, The Squirrelanoids, and Slash. The Turtles also notice Metalhead at the main computer of the base, revealing that Metalhead was actually on their side all along and that he is trying to both gain the turtles' trust and trying to rescue the other mutants. The Kraang, however, quickly catch on to this, and both the Turtles and Metalhead work together to stop the invading droids. Despite the interference of a brainwashed Snakeweed and Spider Bytez, Metalhead manages to rescue the Turtles, releases all of the captured Mutants from their chambers, and manages to re-open the portal back to Earth. Despite the Mutants and the Turtles being able to escape, Metalhead is not able to leave, due to him being the only one to keep the portal open. Despite the pleas of the Turtles, Metalhead orders them to leave, as there is no other choice. After saying goodbye to Donatello for one last time, Metalhead attacks the main computer, destroying several Kraang droids, along with himself in an implosion...

Back on Earth, the Turtles find out that all that remains of Metalhead now is just his completely inactive head (which actually came up through the portal with them). Leonardo apologizes to  Donatello  for not trusting Metalhead so much, and the Turtles give a moment of silence for their fallen robotic ally, though Donatello hints that he might indeed repair Metalhead - someday in the near future...

Trivia

 * Metalhead's beeps and sounds are an homage to the famous astro-droid R2D2 from Star Wars.
 * On the back of the Port-a-Potty Portal there's a spray-painted "42!", which in the The Hitchhiker's Guide to the Galaxy is said to be "The Answer to the Ultimate Question of Life, the Universe, and Everything".
 * Donnie's robot Metalhead constantly grabbing Mikey by the face is a gag that relates to Mikey's friend, Leatherhead, grabbing Donnie by the face in previous episodes.
 * Awkwardly, a few mutants didnt appearin this episode, such as: Rahzar, Fishface, The Newtrailizer, The Rat King, Mutagen Man and Leatherhead.