Birth of Double Prime

With Hot Rod searching for the Matrix on Earth with the Headmasters, Galvatron has become suspicious of what he's up to and so he, Cyclonus and the Decepticon Headmasters travel to the new Decepticon Earth base and meet up with Sixshot, who has Ratbat play back Soundwave's last recording. Soundwave's log records how Hot Rod has gone to Earth to search for the Matrix, but has no idea where it is. Galvatron decides that they have to find Hot Rod before he finds the Matrix, so a group of Decepticons prepare for an attack run.
 

Somehow the Autobots learn of Galvatron's plan, so Ultra Magnus sends out a few squads to counter attack and hopefully buy Hot Rod more time to find the Matrix. He sends out the Technobots to Hot Rod's position, whilst sending out the Protectobots to deal with the near by Combaticons. Ultra Magnus meanwhile leaves with a squad of his own consisting of Inferno, Tracks, Jazz and Prowl.
 

Hot Rod and the Autobots Headmasters are searching through the last possible area the Matrix could be but to their surprise it isn't there. Hot Rod wonders where on Earth it could be but then thinks up a possible answer: Optimus may have hidden it somewhere obvious just to confuse the enemy, and Hot Rod seems to know where it could be.
 

On Athenia, Kup and the others are worried about Hot Rod until Fortress comes in and says that he is going to head to Cybertron and try to find Optimus and tell him that Hot Rod is searching for the Matrix. He can still remember the layout despite it being four million years since he's last been to Vector Sigma. Kup lets him head off.
 

As this is all happening Optimus is still making his way through to Vector Sigma, and finds a trap room which he rather stupidly opens and a load of power leeches attack him. The narrator explains that these leeches suck as much energy out of a robot as they can, but Prime manages to avoid being drained and runs off.
 

On Earth again Hot Rod takes the Headmasters to an energon mining facility, saying that he's picked up massive energy readings so there is a good chance that the Matrix could be there. Before they can go inside the Terrorcons show up, but the Headmasters fight them giving Hot Rod enough time to go inside.
 

Taking a battering, the Terrorcons form into Abominus but then the Technobots finally show up and form into Computron. The two Gestalts fight each other and Abominus is eventually defeated by Computron booting him to the Headmasters, who then throw him face first in the ground.
 

Inside the facility Hot Rod searches for the Matrix and finally finds it fully charged and ready to rock. He grabs it and heads back outside, telling the Headmasters that they have what they came for and that he's going to head to Cybertron via the space bridge whilst they can take care of things here (as in batter Abominus whilst he's down), so Hot Rod runs off...
 

...only to find Galvatron and the Decepticon Headmasters in wait for him. They attack Hot Rod and instead of doing the sensible thing of transforming into car mode and making a quick get away, he runs instead and gets tackled, dropping the Matrix in the process.

 

With the Decepticon Headmasters keeping Hot Rod busy, Galvatron is about to take the Matrix but thanks to the timely arrival of Computron he doesn't get it and instead has to fight the Gestalt, giving Chromedome enough time to take it instead. With Galvatron busy, Hardhead smacks Mindwipe out of the way and he and the other Autobot Headmasters follow Hot Rod to the space bridge whilst Computron keeps the Decepticons out of the way. The Autobots meet up with the Trainbots, and then use the space bridge before the Decepticons can stop them.
 

On Cybertron Fortress has started his search for Optimus and uses some kind of scanner to look for him. He finds Optimus on it and tries to warn him that he is going the wrong way by using telepathy, but it's actually Alpha Trion's spirit that picks this up. Alpha Trion relays this information to Optimus just as he is attacked by several giant mutant rats which Optimus takes out before running off and heading a different way.

Heading through a different route, Optimus and Alpha Trion cross a bridge and finally enter the Vector Sigma computer room. Optimus goes in to try and fix the computer, only to find that Cyclonus and Scourge have somehow gotten to it before him! And because of this, Vector Sigma is on the Decepticon side and has made them more powerful, and to top it off, without the Matrix Prime can't change it back.

As Optimus takes a beating the Autobots arrive on Cybertron and head to Vector Sigma. Meanwhile Fortress finds Optimus and takes out Cyclonus whilst Optimus defeats Scourge. The other Autobots then show up and Optimus praises Hot Rod for finding the Matrix. All the Autobots are about to beat up Cyclonus and Scourge when...

...Galvatron shows up and says he'll take out all the Autobots now the greatest ones of them all are here. He and the other Decepticons start a fire fight so the Autobots take cover and fight back.

Alpha Trion's spirit tells Hot Rod to put the Matrix over his head. He does, and the fight stops as Alpha Trion turns into pure energy and merges with the Matrix, turning Hot Rod again into...

...Rodimus Prime!

With two Primes on the scene you just know someone is going to get hurt, and within seconds the Decepticon Headmasters are all defeated. Galvatron can't believe it and tries to attack, only for both Prime's to dodge his lunge and have Optimus punch him straight in the face.

As Galvatron flies back from the punch Fortress decides to get in on the Galvatron bashing action and promptly throws him straight into a wall. Realising that their leader has been defeated all of the other Decepticons retreat.

With Vector Sigma's condition worsening Optimus tells Rodimus that he must fix it and jumps up, whilst Galvatron manages to free himself and quietly sneaks up on Optimus and tries to tear his head off before any of the other Autobots can react.

Optimus ends up hurling Galvatron straight at Vector Sigma itself, which make it enter a critical phase. Optimus runs up and starts to merge with the computer and fixes it up. The computer blasts out energy everywhere and then returns to it's normal state.

When things return to normal Galvatron gets up, seemingly unaffected by what just happened, and runs off. However, Optimus isn't so lucky and by the time Rodimus and the Headmasters get to him, he turns grey which can only mean one thing: he's died. However before he truly passes away he tells Rodimus that he is a great leader and that he must continue to fight for peace.

The final shots of the episode basically involve the narrator explaining about how Vector Sigma has been saved and that the Autobots must continue to fight. The very last shot of the episode has Rodimus Prime and the Autobot Headmasters transforming and rolling out.

The time scale for this episode is ridiculous. Optimus Prime was seen heading for Vector Sigma at the near start of the previous episode. In the time it took him to reach the actual computer itself:

• Hot Rod managed to go to Earth and search every possible Matrix location (which were at different places in the world), think about how it could be somewhere obvious, go to said obvious place, return to Cybertron and still show up in the main Vector Sigma computer room only a few minutes after Optimus got there.

• Cyclonus and Scourge somehow managed to beat Optimus there despite entering it long after Optimus did.

• Galvatron and the Decepticon Headmasters showed up only a minute or so after Hot Rod did.

The only explanation to this could be that Optimus kind of forgot where he was going (hence all the traps he walks into) and so took a lot longer than he should have.

There's a version of Headmasters out there which includes slightly more colourful language in the subtitles for when Galvatron exclaims he disbelief. I don't know which version that is but I wish I had it.