With the Autobots back at base after Unicron's defeat, Ratchet grimly outlines the situation and speculates that Optimus has reverted to Orion Pax, his pre-Prime self. On the Nemesis, Megatron makes a ship-wide announcement that Orion Pax is to be treated as a guest. Airachnid doesn't think it's wise to let an Autobot on board, but Megatron isn't concerned and has his own plans for Orion. Elsewhere on the ship, Knock Out affixes a new Decepticon Symbol to Orion's shoulder.
Fowler wonders why they can't just track down Optimus's signal, but Ratchet says it hasn't been on their sensors since they left the Earth's core. They must find some way to track down Optimus regardless, so they can somehow restore his memory. The best bet seems to be to use the Key to Vector Sigma but the problem is,Vector Sigma is on Cybertron. Megatron begins to fill Orion Pax in on what's been happening, spinning a yarn about how Orion has been a captive of the Autobots, who are led by the Warlord Ratchet. Orion is shocked at the images Megatron shows him of a war-ravaged Cybertron.
June announces that there's no way Jack is going to Cybertron, but Ratchet says only Jack can use the key to access Vector Sigma. The point's moot anyway, as they don't have any way to get to Cybertron. As Raf points out to Miko that the Ground Bridge barely made orbit, though Miko wonders why Ratchet can't just "turbo-charge" it.
With Megatron finished "informing" Orion, the latter vows to help the Decepticons overcome Ratchet and the Autobots. Megatron has Soundwave remove any incriminating evidence from the ship's data core so Orion can be put to work furthering the Decepticon cause without any risk of him finding anything embarrassing.
Sierra turns up at KO Burger to visit Jack as he works at the drive through, confused that she never sees him outside school. Their discussion is interrupted by Arcee picking him up as his shift ends. Sierra jumps to the obvious conclusion after hearing the female voice, and seems unconvinced by Jack's claim that it's his mother. Arcee reports that they haven't detected Optimus yet.
Megatron discusses their new comrade with Knock Out, specifically his task to decrypt records stolen from the Iacon archives near the end of the War. Knock Out wonders if they shouldn't beef up the security, but Megatron feels that Orion will work better if he feels he is not under threat. In any case, Orion's workstation has been located close to the energon storage, which is under heavy guard, Knock Out is impressed and remarks on that.
Back at base, Ratchet is "tinkering" with the Ground Bridge.
Orion has managed to decode some of the data from the Iacon archives, giving coordinates on Earth of stashed Cybertronian technology, possibly weapons. He is puzzled by the absence of Starscream from the Nemesis as he is stated to be Megatron's second-in-command in the documents, but Megatron claims Starscream is dead. Megatron returns to the bridge, where he tells Soundwave he's concerned that Orion will soon learn the truth and have to be eliminated before he decodes all the Iacon database files since Orion asks a lot of questions, which was a valuable trait in a clerk or archivist, but not in a Decepticon...
Fowler contacts the Autobots to let them know that the Decepticons are attacking one of the military bases they hit two months before. Bumblebee, Bulkhead and Arcee respond, finding Knock Out and Breakdown in the process of stealing a power source. As the pair Ground Bridge out, Arcee races through after them and begins speeding through the Nemesis, bashing Vehicons and hunting for Optimus. Soundwave soon relays her presence to Megatron, and though Airachnid offers to deal with it, Megatron sends Soundwave to ensure the Autobot is escorted off the ship. Alerted by the fighting, Orion emerges from his quarters, but Soundwave manages to Ground Bridge Arcee off the ship just before Orion can see her. Deposited somewhere Arctic, Arcee is soon back at base admitting she didn't succeed in determining the location of the ship or whether Optimus was even aboard. Fowler makes a brief call to yell at them for the human casualties at the base, and tensions among the Autobots soon spill over into arguing. Jack, however, believes they can commandeer the Decepticon Space Bridge once it's complete, and use it to reach Cybertron. The Autobots are doubtful, but determined to try and find the Space Bridge.
Meanwhile, Starscream sneaks back on board the Nemesis to steal a stack of energon. Though he deals with the Vehicons guarding the energon storage, more are on their way, and he's forced to duck into a nearby room. His relief is momentary, as he finds himself face to face with Optimus Prime. Starscream calls out Optimus by his name and points his missiles at Orion...
Megatron: - and the first to address him as Optimus Prime will have their voice box torn out.
— Megatron on his punishments.
Orion Pax: One question Megatron. Why are we called Decepticons?
Megatron: Another craven Autobot scare tactic. The name was meant to demonize us. Instead, we wear it as a badge of honor, for if speaking the truth is deception, then we are gladly guilty.
— Orion and Megatron.
Ratchet: Bulkhead! Bulkhead: What? You needed that!?
— Ratchet and Bulkhead on their frustrations.
Starscream: No! Optimus Prime?
Main Article: Orion Pax, Part 1 Gallery
- Ratchet says that Optimus' signal never reappeared at the end of "One Shall Rise, Part 3". It did, but only for a few seconds between Unicron's death and Optimus leaving through the Decepticon Ground Bridge.
- Ratchet also says Optimus has lost all memories of being a Prime, which means he should remember up until he received the Matrix of Leadership. By that time, Megatron had already started the war, started the Decepticons, corrupted Cybertron, and proved his true nature to Orion. Yet, Orion displays no knowledge of Megatron's fall to evil, the Decepticons, Cybertron's shutdown, and still regards him as a friend and teacher. Arcee comes close to bringing this up, but ultimately, the issue is glaringly ignored.
- During his first appearance, the scar on Starscream's right cheek is missing. In the next scene however, it's suddenly there. It also disappears when the lights are flickering after he killed two Vehicons.
- The Vehicons fail to notice that Starscream is flying in formation behind them, and don't hear him land with them inside the ship, even though on both occasions Starscream is no more than a dozen or so meters behind them.
- When Starscream encounters Optimus and prepares to attack him, the sound of laser blasters charging up can be heard, even though he doesn't use them. In the next episode, the sound is gone.
- Throughout the episode, multiple characters refer to Orion Pax as an archivist, but each one of them mispronounces the word as "ar-KIVE-ist." The correct pronunciation is AR-kiv-ist, even though the adjective archival, the verb archive, and the noun archives all use the long I sound. This is a common mistake among people not in the library/archives field (and a huge pet peeve among those who are). The error will be repeated in later episodes.
- A 12-minute sneak preview of this episode was made available On Demand on February 10, 2012.
- Polygon resolved the issue of the seemingly empty Jasper with roving cars!
- Arcee nearly blew her cover while balancing in the drive-thru without her holographic driver touching the ground. Earth bikes can't do that, Arcee.
- One has to wonder why Megatron would have told Optimus that Starscream was dead, if he was also prepared for Starscream to return alive.
- The Decepticon Ground Bridge seems to be able to open anywhere inside the ship, since Arcee enters in the middle of one hallway, only to be sent back out at the end of a completely different one.
- Despite previously beating Starscream to a pulp for his attempted betrayal, Megatron still allows Airachnid to serve as his subordinate - though his brief scolding of her implies he's well aware of her treachery. This would indeed eventually catch up to Airachnid.
- Megatron's explanation for Decepticons' name origin is not as unlikely as it may seem. It was not unheard of soldiers adopting seemingly demonizing names as "a badge of honor", for example "Rats of Tobruk" (Allied soldiers defending Tobruk from Germans), "Night Witches" (Soviet all-female night bombers unit) or "Tunnel Rats" (American soldiers penetrating Vietcong's tunnels during Vietnam War).
- Adaptations of this episode include a screen-capture-style comic version as part of The Orion Pax Saga.
- Fowler mentioned only 15 men are injured when Decepticons are attacking the military base. However, in the attack, Breakdown and Knockout use their blasters that destroyed some tanks, causing them to explode. It will be really weird for the operators in the tanks to survive.
Orion Pax, Part 1}}