"''I can lead you directly to Unicron's spark: the very heart of his darkness!"
Optimus battles a horde of Unicron's stone avatars, but when he's overwhelmed, the Autobots lend a hand. Optimus initially disagrees, but Ratchet points out that if Optimus doesn't survive, Earth dies
. Optimus relents and the Autobots make their way through hordes of progressively larger avatars, until faced with an enormous titan of an avatar. The Autobots are quickly overwhelmed, and Unicron nearly kills Optimus before Megatron saves his nemesis.
After Optimus makes it clear he's still very open to killing Megatron outright, Megatron offers to ally with the Autobots to defeat Unicron. Optimus correctly surmises that this is just out of pride; no one but Megatron can conquer Earth. Megatron admits that after Unicron's defeat, he will resume hostilities against the Autobots. Optimus slowly comes around to the idea of allying with Megatron, despite plenty of arguments to the contrary from Ratchet and the others. The group realizes that they will have to Groundbridge to the Earth's core to defeat Unicron, meaning they would have to bring Megatron into Omega-1.
Raf and Ratchet explain the tricky nature of trying to defeat Unicron: he is
the Earth's core, after all, and attempting to remove him from his current physical location could bring about the apocalypse they're trying to stop. After Optimus and Megatron agree that they can only defeat Unicron with the Matrix of Leadership, Unicron's avatars return. The Autobots retreat to their base while Megatron dukes it out with the avatars for the time being. At the base, Optimus assures the group that bridging Megatron directly to the base will prevent him from learning its' location. Jack questions what will happen to Optimus when the Matrix is emptied stopping Unicron, but Optimus evades the answer and rallies his troops to follow him and Megatron to the core.
Ratchet hides the humans when Megatron is finally bridged to the base, but Raf, sore from his near-death experience, runs towards Megatron, who is impressed with humanity's resilience, and also acknowledges Jack. Miko swears vengeance on Megatron should he double-cross the Autobots before she's dragged away by Fowler. Megatron and Ratchet input the coordinates for the Groundbridge, while Optimus asks Jack to hold onto a small device he calls the key to the Groundbridge power supply. Optimus entrusts it with Jack out of admiration for how much he's matured since they met.
Optimus, Arcee, Bumblebee, Bulkhead, and Megatron depart through the Groundbridge and arrive inside Unicron. Arcee questions when Unicron will realize their presence, but Megatron snarls that he already knows.
To Be Concluded...
- Attack of the 50-Foot Whatever: The first stone copies of himself Unicron made were already much larger than normal transformers, but the giant sized ones make them look like insects.
- Berserk Button: Megatron claims the past doesn't matter so long as Unicron functions. Ratchet snaps at the tyrant for trying to push everything he's done to Cybertron and the Autobots under the rug.
- Big Damn Heroes: Played straight at the beginning by Team Prime.
- Big "NO!": Arcee yells out this when Unicron was about to step on Optimus.
- Brutal Honesty: Megatron admits that when Unicron is defeated, he'll get back to work trying to conquer Earth.
- Continuity Nod: Megatron remembers Jack, who spared his life, in "Rock Bottom".
- Arcee mentioned how Megatron's attempts to conquer Cybertron destroyed it.
- Enemy Mine: Megatron makes an alliance with Optimus and the Autobots to defeat Unicron
- Eyes Do Not Belong There: There's one inside Unicron's spark chamber.
- Foreshadowing: Miko warns Megatron of her wrath should he cross the Autobots.
- Honor Before Reason: Optimus tries to stop the Autobots from helping him fight Unicron's avatars, believing it's just his fight. Ratchet points out that for Earth to survive, Optimus must survive too.
- Reality Ensues: Megatron's Brutal Honesty regarding conquering Cybertron once the alliance is over, as well as the notion that trying to remove Unicron from the Earth would trigger an apocalypse they can't hope to stop.
- Villainous Rescue: Megatron rescues Optimus from Unicron.
- Zerg Rush