When Optimus Prime becomes sick from an old virus, Team Prime must find a cure and aid their sick leader before it's too late.
Ratchet reports that his scans have located the Decepticon warship while experimenting with different frequencies. Arcee thinks they should strike now, but Ratchet says he's also detected an Autobot emergency beacon, and Optimus Prime decides they should check that out first. He and Ratchet arrive at a centuries-old crashed Autobot ship and venture inside. Though they expect there may be survivors, they find the crew already dead. Ratchet's scans reveal that the crew didn't die in the crash, but had succumbed to a deadly cybertronian virus commonly referred to as "cybonic plague". As the ship shifts, a deceased Autobot hanging from the ceiling drips plague-imbued energon onto Optimus.
Later at base, Optimus lays stricken while the others discuss the situation. The plague was developed as part of the Decepticons' Biological Warfare Program, specifically by Megatron himself, and Ratchet thinks they might be able to find information on how to stop it in the Decepticon databases. Arcee and Bumblebee Ground Bridge onto the Decepticon ship and, narrowly hiding from Knock Out, enter the ship's laboratory. Inside, Arcee scours the database, but fails to find a cure for the plague. While she's doing so, Bumblebee stumbles on something just as important—the comatose body of Megatron! Arcee is ready to finish Megatron off then and there, but Ratchet has a better idea—enter Megatron's brain and retrieve the plague cure from his very mind. Ratchet knows of a procedure to create a cortical psychic patch. Though such procedures have been developed by decepticons and banned by Autobots for years, it will get them into Megatron's brain, and Bumblebee is willing to try it.
On the ship's bridge, Starscream complains that the ship's electromagnetic shielding has not been fixed, and directs the Vehicons to hurry up and do so before the Autobots detect them (it's a bit late for that). Afterwards Starscream has a private word with Knock Out, suggesting that the Decepticons deserve a leader who is conscious, and the pair come to an understanding whereby Knock Out will be Starscream's new second-in-command.
Arcee plugs Bumblebee into Megatron, and Bumblebee finds himself in a simulation of the cybertronian city and the decepticon capitol, Kaon. Ratchet creates a communications downlink, so they can monitor what Bumblebee is doing. Bumblebee wanders though Kaon until he finds what appears to be Optimus, but is just a figment of Megaton's imagination that can't see or hear Bumblebee. Megatron appears and slays the false Optimus, who dissolves into teal-colored smoke. Another Optimus appears out of a rock wall, and as Megatron fires his fusion cannon, Bumblebee jumps in the path of the blast, only to find it passes right through him to slay the imaginary Optimus. Megatron, however, has seen Bumblebee and attempts to strike him, but his blows pass clean through Bumblebee. While Megatron is trying to work out what's going on, Optimus, Bulkhead and another Bumblebee appear, all figments of his imagination. Ratchet then clarifies that this is not good. Megatron destroys them, but begins to figure out everything. The Autobots have awakened Magatron from his fantasy world, and he realizes that he's in his own subconscious.
Arcee becomes anxious when Starscream, Knock Out and Soundwave enter the lab, though the two Autobots are hidden well enough that the Decepticons don't see them. Starscream is determined to put on a show for Soundwave, to convince his fellow Decepticon that Megatron is beyond saving. He and Knock Out attempt to persuade Soundwave that putting Megatron out of his misery is the best thing to be done. Arcee and Ratchet overhear their conversation, and Ratchet says terminating Megatron will permanently separate Bumblebee's mind from his own body.
In the dream world, Megatron ponders what has happened to him, and finds out from Bumblebee about the Space Bridge explosion. Without anymore time, Bumblebee relays the news about Optimus' cybonic plague infection. Megatron sees amusement in the irony that after all these eons of battle, Optimus will be felled by a virus, but Bumblebee plays on his desire to finish Optimus himself.
Starscream is about to pull the plug on Megatron when Soundwave points out the psychic patch cable. Starscream begins following it, as Arcee observes from her hiding place.
Megatron briefly shows Bumblebee the formula for the virus cure, but will only share it if Bumblebee can release him from his mental prison. Unknown to Megatron, Ratchet can still see everything Bumblebee sees. Having ganked the formula they need to save Optimus, Ratchet tells Arcee to cut the link pronto. Megatron's dream world begins to disintegrate and the Decepticon leader launches himself at the disappearing Bumblebee.
Bumblebee returns to his own body and comes around as Starscream finds them. And, as they escape through the Ground Bridge, Arcee blasts one of the cables attached to Megatron. Starscream is actually pleased that Megatron has flatlined as a result, but at Soundwave's insistence has Knock Out reconnect the cable.
A newly-cured Optimus stands up and the Autobots celebrate, but Optimus insists the celebration should be for Ratchet and Bumblebee, the two heroes who really pulled out all the stops to help Optimus Prime. On the Nemesis, Knock Out observes that Megatron is no longer exhibiting any brainwave activity — there's no one home. Unknown to the others, Megatron now resides in Bumblebee's head...
Main Article: Sick Mind Gallery
- Peter Cullen as Optimus Prime
- Frank Welker as Megatron
- Sumalee Montano as Arcee
- Kevin Michael Richardson as Bulkhead/Trooper
- Jeffrey Combs as Ratchet
- Steve Blum as Starscream
- Daran Norris as Knock Out
- Josh Keaton as Jackson Darby
- Tania Gunadi as Miko Nakadai
- Andy Pessoa as Rafael Esquivel
Ratchet: I will not allow Optimus to pass knowing that Megatron will outlive him!!!
Arcee: Ratchet I would lay down my life for Optimus. Anytime. Anywhere. But a mind body split...
Bumblebee: *Beeps to volunteer*
- Ratchet, Arcee and Bumblebee prove that they would do anything for Optimus Prime to be safe.
Starscream: An inglorious fate that he should remain in this vegetative state...
- Starscream on Megatron's state.
Starscream: You scratch my back, I scratch yours.
- Starscream making a deal with Knock Out.
Megatron: If this is my subconscious... WHAT ARE YOU DOING INSIDE MY HEAD?!
- Megatron becoming self-aware.
Megatron: Such irony! But after ages of endless battle, the mighty Optimus Prime is felled by a simple virus from a distant past?!
Megatron: And what makes you think that I would save the life of my oldest enemy?!
Starscream: Speak now, or forever hold your peace.
- Starscream to Soundwave, who still does not say a word.
Megatron: I'm out....or should I say in?
- Megatron giving us some nightmare fuel.
- Kaon, the Decepticon capital on Cybertron, was first mentioned in the Dreamwave Generation 1 comics.
- "One shall stand, one shall fall" is used for the second time in this series, and the billionth in the franchise overall.
- Megatron asks whether or not he "still functions".
- Megatron refuses to hand over the formula for the cure to the plague unless Bumblebee helps him escape, saying he will let Optimus "fade to gunmetal grey."
The first showdown between Megatron and an Optimus illusion is reminiscent of the title sequence.
- Cybonic plague is a reference to bubonic plague.
- Bulkhead says that Megatron is "pushing up lugnuts". This is a modification of the human phrase, "pushing up daisies", although it doesn't make much literal sense.
- Oddly enough, Starscream uses two common human phrases, both quoted above. Perhaps Soundwave gets cable?
- The way the infected energon makes contact with Optimus Prime via his optics is reminiscent of the horror film, 28 Days Later, in which the character Frank is infected in the same manner when a drop of infected blood falls into his eye.
- The spot where the downed Autobot ship was shown on Ratchet's map is in a temperate climate. Meaning it should have been in a forest or grassland, not a desert.
- When Knock Out says that there is no brainwave activity, one of the monitors next to Starscream shows brainwave activity in Megatron.
- Since Megatron's dream was, presumably, taking place before the cortical psychic patch, why is it destroyed once the patch is broken? Shouldn't Bumblebee be the only thing in it to disappear?
- None of the characters in this episode transform at any point.
- This episode was available to watch prior to its intended airdate on some cable providers' Video On Demand services.
- Adaptations of this episode include a prose version as part of Airachnid Attacks!.