-->"I... never imagined it would end like this."
--> -- Ratchet

At the Omega Lock, everyone is locked in a stand-off. The Decepticons have Jack, Miko and Raf captured and are ready to expose them to Cybertron’s toxic atmosphere, lest the Autobots hand over the Omega Keys. Though the kids are ready to sacrifice their lives just like the Autobots always have been, Optimus declares they will never forsake their human allies, lays down the Star Saber, and the Autobots likewise stand down. Megatron decrees a one-at-a-time exchange. Knock Out delivers Miko to Bulkhead, and Soundwave delivers Raf to Bumblebee. As Jack was deemed worthy of the Matrix of Leadership, Megatron decides he’s worth two Omega Keys. The exchange complete, Megatron has Team Prime surrounded by Vehicons. On Earth, Ratchet quickly hangs up on June Darby, both unaware the kids are on Cybertron.

The Decepticons insert their Omega Keys into the Omega Lock, heralding the dawn of the “Age of the Decepticons”, according to Megatron. The power of the Omega Lock restores a destroyed building to a pristine state, as a test run. Optimus requests to take the kids home, but Megatron gleefully warns him that they’ll be safer on Cybertron. Starscream opens a space bridge over the Omega Lock, and the resulting beam fires through it, hitting Earth outside Jasper, to June’s shock. The Autobot base’s systems also go haywire from all the energy, making a communications blackout. A shaken Optimus reveals that the Omega Beam will not restore Earth, but cyberform it into a metallic world fit for Cybertronians, destroying ''all'' native life.

As the kids scream for their home, and as the Decepticons ([[OOCIsSeriousBusiness even SOUNDWAVE]]) share a laugh, Optimus finally makes a decision. He bursts through the Vehicons surrounding him, grabs the Star Saber and runs for the Omega Lock. The Decepticon leader tries to retaliate with the Dark Star Saber, but quickly loses the fight and has his Prime arm chopped off by Optimus. The remaining Decepticons put up a desperate defense of the Omega Lock, but Knock Out, Starscream and Soundwave stand no chance against the enraged Prime. To everyone’s shock, Optimus destroys the Omega Lock with the Star Saber. The Omega Beam on Earth dissipates, and Optimus is able to finally call Ratchet for a space bridge. The shocked team retreats, and the Decepticons pull themselves together to find the Omega Lock a burning ruin. Knock Out’s quip is stopped by an enraged, and hurt Starscream, who sends him to look after the wounded Megatron. Starscream rages over the loss of Cybertron, clearly emotionally distressed, but stops when he hears his master cackling maniacally. As the audience no doubts dirties their pants, Megatron only smiles evilly… “They can run, but they can never again run ''home''!”

Ratchet is shocked to see the shaken Autobots returning to base with the kids, and even more so when they report that Optimus destroyed the Omega Lock. Losing his composure, Ratchet condemns Optimus for destroying the only chance they had of restoring their home. Any attempt to calm him down only hurt him even more as he laments the sheer loss they've taken.

-->'''Ratchet:''' All of our struggles and energon spilled and countless sacrifices, for '''''NOTHING'''''!?

Arcee points out the very, very unfortunate fact that the Decepticons have hit on the idea of using the kids in the war. Fowler then calls the base, positively livid and demanding to know what they’re dealing with. When Optimus asks what he’s talking about, Fowler tells him to step outside and look. The Autobots ascend to the mountain-top, and to their surprise find a massive, 5.5 mile-high Decepticon fortress now stands on their doorstep. Fowler arrives in his helicopter as Optimus observes that Megatron was able to establish a new fortress on Earth, even if he didn’t succeed in Cyberforming Earth. Fowler asks why he’d have it in the evacuated Jasper, but as Bumblebee points out the approaching ''Nemesis'', the answer becomes horribly clear: the Decepticons have finally found the Autobot base.

Missing his right arm, Megatron rallies his troops, damning Optimus for destroying their chance to revive Cybertron, and launches the invasion by ordering his Decepticons to transform and rise up. Starscream gleefully leads his new Seeker armada and the Insecticon hordes in the assault. The Autobots put up a desparate defense of their home, but Optimus orders a retreat into the base. Undeterred, Fowler [[MisfitMobilizationMoment proves his loyalty to his team]] and flies his helicopter straight into battle against the Decepticons. As the base is shaken by the attacking armies, Optimus announces to Ratchet and the kids that the Decepticons have found them. Outside, Fowler is quickly outgunned and cornered, but suddenly the ''Jackhammer'' streaks in to save his hide: Wheeljack arrives and joins the battle, declaring himself to always be on the same team as his surprised comrades.

Realizing Fowler and Wheeljack can only buy them so much time, Optimus declares that Omega-1 is lost. He orders the team split up and Groundbridged across the country to evade capture - survival is their only priority now. This decision is just in time, as in the midst of battle, Fowler watches as the ''Nemesis'' moves over the Autobot base, with a silent Megatron observing from the ship’s nose. Bumblebee and Raf are first to bridge out, and Jack and Miko just barely are able to exchange a silent farewell as they evacuate the rumbling base. Outside, June is arriving at the site of the raging aerial battle over Jasper, and is quickly cornered by a Vehicon. Fowler tears away from the battle and saves her, spiriting her away in his helicopter. Overhead, Wheeljack is outnumbered and being chased by Starscream and his armada. Though he’s put up a good fight, Wheeljack is sent crashing to the ground by the Air Commander. Team Prime has lost the aerial battle over the base.

Smokescreen departs on his own, and Ratchet is next to evacuate. When he asks what Optimus will do, his leader says he will stay behind to ensure Megatron won’t follow. Realizing the implications, and still hurt from the loss of Cybertron, Ratchet sadly says he never imagined it would end like this, leaving a clearly scared Optimus alone in the doomed base. The ''Nemesis'' begins deploying and prepping a colossal cannon to fire. As Optimus readies the Star Saber, the cannon reaches full strength, and June and Fowler watch from the latter’s helicopter, Megatron looks on in apathy. Just as the Groundbridge is destroyed, the ''Nemesis'' fires on the base, completely destroying the mountain and the base inside. As the base erupts into flames, and everything changes, June looks on in horror, unaware of her son’s fate, and a devastated Fowler pulls away from the scene.

Megatron and Starscream fly down into the flaming ruins, landing on the Autobot sigil. The two gloat at their victory, and not far away, Optimus’ battered arm can be seen sticking out of a pile of rubble.


!!Tropes

* AlienInvasion: [[spoiler: Megatron thoroughly throws off TheMasquerade and all but outright declares the Cybertronian presence on Earth with the building of "New Kaon".]]
* AnArmAndALeg: [[spoiler:Optimus uses the Star Saber to slice off Megatron's appropriate Prime hand]].
* AttackAttackAttack: Spoken by Starscream leading his armada.
* [[spoiler: TheBadGuyWins: For the end of this season, at least.]]
* BackToBackBadasses: [[spoiler:Fowler and Wheeljack during the aerial battle]].
* {{Battlecry}}: "Decepticons, transform and rise up!" The phrase was first coined in ''TransformersAnimated'' and this episode marks its first use in this series.
* BigDamnHeroes: [[spoiler:Wheeljack arrives to provide more air support, saving Fowler in the process]]. For his part, [[spoiler:Fowler saves June from a Decepticon]].
* BondOneLiner: Starscream's "And ''that's'' how you [[spoiler:wreck a Wrecker!]]"
* [[spoiler: BreakingTheFellowship: Optimus orders Team Prime to scatter across the country to ensure that the Decepticons cannot find them.]]
* DarkestHour: The episode title is very appropriate. [[spoiler:Optimus is forced to destroy the Omega Lock, preventing Cybertron from being restored. The Decepticons take over Jasper, Nevada and launch an attack on the newly discovered Autobot Base. The Autobots are forced to split up before the base is destroyed, with Optimus staying behind to keep them from being followed. The last shot shows Megatron and Starscrem in the ruins of the Autobot Base, while one of Optimus' hands is in the rubble.]]
* DarkReprise: The series' main theme has a much darker, much more painful feel to it as it plays as the horrible sight of the [[spoiler: destroyed Autobot base sinks in as June and Fowler watch in horror]].
* DeadHandShot: [[spoiler: Optimus Prime]]
* [[spoiler: DownerEnding]]
* DudeNotFunny: In-universe example. [[spoiler: After Optimus Prime destroys the Omega Lock, Knockout makes a joke about cancelling the welcome home party. Starscream then strikes him and orders him to attend to Megatron's wounds]].
* EvilTowerOfOminousness: [[spoiler: New Kaon.]]
* HeroicBlueScreenOfDeath: [[spoiler: Optimus destroyed the Omega Lock to save Earth. Everyone else tells him that Optimus had no choice, but Ratchet, in obvious pain, lashes out about how Cybertron is now unsavable.]]
-->'''Ratchet''': Optimus...we ''needed'' that.\\\
[[spoiler:'''Ratchet:''' All of our struggles and energon spilled and countless sacrifices, for '''''NOTHING'''''!?]]
* {{Hypocrite}}: For all of his rage towards [[spoiler: Optimus for destroying the Omega Lock to save Earth. The doctor seems to conveniently forget that Optimus would not have been forced to make the decision in the first place, if he had done as Miko suggested and picked the children up from school himself.]]
* NiceJobBreakingItHero: [[spoiler:Optimus destroying the Omega Lock. He did it to save Earth, but doing so leaves Cybertron a dead world.]]
* NoOneCouldSurviveThat: Starscream is awfully confident that he [[spoiler:wrecked a Wrecker when he shoots down Wheeljack]]. [[spoiler:However, as it's going down, the ''Jackhammer'' is shown going behind a nearby mountain and no crash is even seen or heard. Turns out in the Season 3 opener he ''did'' survive that]].
* NothingIsTheSameAnymore: This episode totally changes the dynamic of the show [[spoiler:the Omega Lock was destroyed, Megatron has peeled back the masquerade concerning the Autobot/Decepticon war, the team has been scattered, Wheeljack has been shot down and the base is blown up with Optimus inside.]]
* [[spoiler:[[IDidWhatIHadToDo Optimus Did What He Had to Do]]: "Right decision or wrong, what's done is done..."]]
* SadisticChoice: Two in quick succession for Optimus:
** [[spoiler: The first of these is whether to let the 'Cons expose Jack, Raf and Miko to Cyberton's toxic atmosphere, or give the Omega Keys over to Megatron and let him revive Cybertron in his image.]]
** [[spoiler: Then he has to decide whether to destroy the Omega Lock and condemn Cybertron permanently, or let Megatron terraform Earth in the image of the Decepticons, destroying the human race in the process.]]
* ShipTease: [[spoiler: Miko gives Jack a longing look as she and Bulkhead drive through the [=GroundBridge=] to parts unknown, and Jack spares Miko a brief glance.]]
* WhatTheHellHero: Ratchet is very angered and saddened by [[spoiler:Optimus destroying the Omega Lock]]. He's not shy about expressing it, either.
-->'''Smokescreen:''' You weren't there, Doc, and it's not your place to second guess a battlefield decision.\\
'''Ratchet:''' IT MOST CERTAINLY IS! There HAD to be another way!\\
[[spoiler: '''Jack:''' Ratchet, it wasn't that simple!\\
'''Raf:''' Megatron was using the Omega Lock to attack Earth!\\
'''Miko:''' Optimus saved our planet!\\
'''Ratchet:''' WHAT ABOUT ''OUR'' PLANET??]]
* YouCantGoHomeAgain: [[spoiler:To stop the cyberforming of Earth, Optimus is forced to destroy the Omega Lock, permanently leaving Cybertron a barren wasteland. Lampshaded by Megatron, who says that they can run, but they can never run ''home''.]]
** [[spoiler:It could apply to the Autobots' earth base being destroyed and the team being scattered across the United States.]]
** [[spoiler:It also specifically referred to Optimus's actions; he destroyed the Omega lock, forever dooming Cybertron. No matter what happens Megatron's cause now has a legitimate reason to persecute the Autobots. They really can't ever go home again.]]
-----
-->"Neither did I, old friend."
--> -- Optimus Prime