-->All units: Optimus Prime has returned!
--->- '''Ultra Magnus'''

Team Prime wages war against the Decepticon citadel, but with the Decepticons having a major advantage over them, someone needs to pull off an unthinkable miracle if the Autobots are to win.

!!Tropes:
* BatmanGambit: In "Darkmount, NV", Jack unwittingly attracted a couple of Decepticons when sending a text to his mom about his well-being. This time, Ratchet has him and Miko call in random places of the US using a Decepticon frequency, to spread the forces of Darkmount thin enough to attack through.
* BigDamnHeroes: Optimus flying into Darkmount, just as Megatron ordered the prisoners executed and each plasma cannon fired at the nearest human cities.
* BigDamnReunion: With Optimus back in action, thanks to Smokescreen, Team Prime is whole once again with Ultra Magnus and Wheekjack joining them.
* BlastingItOutOfTheirHands: Megatron shoots Ultra Magnus' hand-held {{BFG}} when he tries to attack the fusion cannons' power core.
* CallBack: [[Recap/TransformersPrimeS2E3OrionPaxPart3 "Megatron, BE GONE!"]]
** Ratchet sending Predaking to the Arctic is a call back both to how the Autobots sent the Scraplets there and how Soundwave once tricked Arcee off of the Nemesis.
** As part of their ploy to lure the Decepticons out, both Jack and Miko use their cell phones, just Jack unwittingly did in the season opener.
** Optimus grabs a transformed Megatron by the tail fins, whirls him around and tosses him (into Darkmount's power core no less) in much the same way Megatron did with Starscream after his own return in ''Out Of His Head''.
* CameBackStrong: Optimus, thanks to the Forge of Solus Prime and Smokescreen refusing his destiny.
* CasualDangerDialogue:
-->'''Shockwave:''' (''as Darkmount collapses all around him'') Soundwave, I require a Ground Bridge.
* CurbStompBattle:
** He tries his best, and even lands a hit or two, but Ultra Magnus ultimately gets a pretty one-sided thrashing from Megatron, who even puts down Magnus as "no Optimus Prime."
** In turn, Megatron gets his aft handed to him quite thoroughly by the rejuvenated Optimus.
* DeusExitMachina: Once Predaking is sent out, Ultra Magnus quickly gets his attention and orders Ratchet to open the [=GroundBridge=]. Predaking gets dumped in the Arctic and is quickly frozen.
* DidntSeeThatComing: Megatron and later Optimus are admittedly surprised to see Ultra Magnus on Earth.
* DynamicEntry: With security too tough for the Stealth Team to get past, Ultra Magnus gets into the power core by jumping off a roof and through the window.
* EurekaMoment: As Optimus starts to pass on, Smokescreen gets an idea and looks at the Forge of Solus Prime.
* HellYesMoment: "All units, Optimus Prime has returned." Cue the Autobots and their allies celebrating.
-->'''Ratchet:''' Thank the [=AllSpark=]!
* HesBack: And feeling Prime.
* HoistByHisOwnPetard: Optimus sends Megatron flying and then frying inside his own plasma cannon's energy channel, causing the cannon to malfunction.
* HopeSpot: Ultra Magnus is about to destroy the power core, only for Megatron to blast his rifle.
* IDidWhatIHadToDo: Smokescreen admits that he did what was necessary to bring back Optimus, at the cost of the Forge's remaining power.
-->'''Ratchet:''' Is it true the Forge has been drained of its power? Then any hope of rebuilding the Omega Lock has truly been lost.\\
'''Smokescreen:''' I... did what I felt was right.\\
'''Ratchet:''' [[BaitAndSwitchComment And your instincts have again proven to be quite sound]].
* InstantExpert: Optimus has no trouble with his new flight-mode or weaponry after being upgraded by the Forge.
* LeaveNoSurvivors: Megatron says something along these lines at one point.
* LockAndLoadMontage: After Ultra Magnus issues the order to do exactly this.
* MilitariesAreUseless: Averted in the most epic way possible. When Optimus Prime disables Darkmount's fusion cannons, a squad of USAF jet fighters led by Agent Fowler launches a barrage of missiles that send the whole fortress collapsing to the ground.
* MythologyGag:
** [[WesternAnimation/TheTransformersTheMovie This isn't the first time Optimus is dead]] or, in this case, ''dying'', [[Recap/TransformersG1TheReturnOfOptimusPrime before rising up again]].
*** Nor is it the [[Anime/TransformersCybertron first]], [[WesternAnimation/TransformersAnimated second]] or [[Film/TransformersDarkOfTheMoon third]] time that an Optimus has gotten a jetpack upgrade.
** Ultra Magnus can't deal with Wrecker style.
** Megatron refuses to [[Franchise/TransformersGenerationOne retreat]], even when the battle has been lost. Ironic, huh?
* NiceJobFixingItVillain: Starscream's neglecting to destroy the ''Harbinger'' after rejoining the Decepticons is finally brought to the forefront here, to Megatron's rage.
* OhCrap: Subtle, but Megatron and Starscream's reaction to seeing Optimus Prime ''flying'' towards them.
* PretenderDiss: After winning their fight, Megatron dismisses Ultra Magnus as "no Optimus Prime" and drags him away for questioning.
* SayMyName: Megatron, while dogfighting Optimus, angrily screams Optimus' name while charging at him.
-->'''Megatron''': OOOOOOPTIMUUUUUUUUUUUUUUUUUUS!!!!!!!!
* ScrewDestiny: When Smokescreen is faced with accepting the Matrix of Leadership and letting Optimus die for the greater good, he chooses to sacrifice Cybertron's future to save Optimus (and deal a devastating blow to the Decepticons as a result).
* ScrewThisImOuttaHere: Shockwave, once things go badly.
-->"Soundwave, I require a ground bridge."
* ShoutOut: The jet fighters backing up Fowler are [[Franchise/GIJoe Skystrikers]].
* SkewedPriorities: Megatron refuses to retreat, even as Darkmount literally falls apart around him. Starscream has better perspective and carries out the retreat.
* StatusQuoIsGod: The Autobots are fully reunited, Darkmount has been reduced to rubble and the Decepticons have escaped on their ship. The Forge of Solus Prime is spent of its energy, the [[InfinityPlusOneSword Star Saber and Dark Star Saber]] are apparently lost (technically, the Star Saber is just on the warship, unavailable to either party), and Predaking is frozen solid in the Arctic. All that's needed for business as usual is for the Autobots to find a new base, which is provided [[Recap/TransformersPrimeS3E5ProjectPredacon in the next episode.]]
* TheStoic: Shockwave reacts to Darkmount falling apart right on top of him by calmly telling Soundwave he needs a [=GroundBridge=] and slowly walking into the portal.
* TacticalWithdrawal: Despite Megatron's [[VillainousBreakdown protest]], Starscream orders a full retreat to maintain hope of winning the war another day.
* ThisCannotBe: Ratchet's reaction to picking up a ''flying'' Autobot signal. Starscream has a similar reaction when seeing who it is.
* TooPowerfulToLive: {{Implied}} when an act of subterfuge leads the Predacon dragon to be groundbridged by Ratchet to the arctic in order to take it out of play where it would have otherwise singlehandedly defeated the Autobots.
* UseYourHead: During their duel, Megatron sends Magnus flying across the room with a single headbutt.
* WhatWereYouThinking: When Starscream discovers that the Autobots are using his old hideaway in the '''Harbinger''', Megatron rightfully chews him out for leaving a place with functional Decepticon technology unsecured.