The episode picks up where part one left off. Optimus Prime is surrounded by several rocklord versions of Unicron, preparing for attack. Ratchet says that their on their way but Optimus tells them to stay at base because he is Unicron's target.
After several blows, Optimus is ganged up against Unicron, who then prepares the finishing blow when Arcee, Bulkhead and Bumblebee arrive through the spacebridge to help. Optimus berrates them from jumping in and Arcee suggests that Optimus be the one to retreat. Prime explains that since Unicron is the earth, he can find him anywhere, even at base, but he concedes to allowing the others to step in and take charge this one time.
As the Autobots run through several of the rockforms of Unicron until a larger one emerges from the ground, prompting their only alternative: knocking it down head on.Unicron's form brings the Autobots down easily but it's head gets blown off just before he can step on Optimus. As Bulkhead, Bumblebee and Arcee question who caused the hit, they are surprised to see Megatron.
Ratchet immediately suspects Megatron of alligning with Unicron only to be told how he saved Optimus' life. Megatron purposes a temporary truce between the Autobots and Decepticons against Unicron, having a difficult time convincing them of his intensions dispite his brutal honesty but he eventually gets Optimus to agree to the truce and even devises a plan with them to stop Unicron: Get to the core, with Megatron's help, then use the power of the Matrix of Leadership on Unicron's spark, sending him back into stasis. An even bigger form of Unicron compiles and Megatron offers the keep it busy while the Autobots make up their mind whether or not to trust him.
Back at base, Optimus assures everyone (mainly Ratchet and June) that Megatron would only be inside the base long enough to enter the coordinates to the core and not a moment longer, also adding that groundbridging him to the base would keep their location hidden. Megatron enters the groundbridge as the Autobots hide the humans, much to Miko's objection, but Raf is the one who rushes out to him angrily. Megatron remembers what he did to Raf and remembers Jack from the cave in, Miko threatens Megatron before being taken back by Agent Fowler.
As Ratchet watches Megatron enter the coordinates, Optimus asks Jack to hold onto a key for him, telling him that it is the key to the groundbridge generator and due to the maturity that Jack has displayed since meeting them, Optimus trusts him to keep it safe until his return.
Optimus, Arcee, Bumblebee and Bulkhead enter the groundbridge and into the core with Megatron leading the way, noting that Unicron may know of their pressence, which it does.
To Be Concluded...