Transformers: Robots in Disguise - Plot

Plot

Megatron captures Dr. Onishi, and the Autobots ally themselves with his son, Koji, vowing to safely recover him from Megatron's clutches. An assortment of plans by Megatron to steal the Earth's energy ensue, led by his subordinate, Sky-Byte, but are stopped by the Autobots, including the newly-introduced teams, Team Bullet Train and the Spy Changers. Probing Doctor Onishi's mind, Megatron discovers the significance of an ancient cave system, in which the Autobots discover a coded microchip belonging to the Doctor. After scuffles involving the new Autobot troops Skid-Z and Tow-Line, the microchip leads the Autobots to the Cave of the Dragon, where they discover a mysterious artifact of Cybertronian origin.

Further information decoded from Dr. Onishi's microchip leads the Autobots to the site of a crashed Cybertronian spaceship containing six protoform Autobots. But Megatron has also learned of the ship through his mind-probes and attacks, capturing the Autobots and taking them to a nearby military base, where he scans vehicle modes for each of them and infuses them with his own Spark energy, creating the evil Decepticons. The final Autobot scans Optimus Prime in addition to the tanker truck that will be his alternate mode, creating Scourge, a twisted "evil twin" of Optimus. Several battles with the Decepticons ensue, as Sky-Byte grows steadily jealous of the attention Megatron heaps on his new warriors. Amidst battles between the Decepticons and the newly-promoted Autobot subgroup, the Build Team, Sky-Byte attempts to prove his worth by holding a tower of humans hostage in exchange for the Autobots' O-Parts, one of which is the artifact from the Cave of the Dragon. The plan meets with failure, but when Sky-Byte saves his hostages' lives, Koji begins to think he might not be all bad. Subsequently, Ultra Magnus, the bitter brother of Optimus Prime, arrives on Earth to claim the Matrix in Prime's possession, leading to an injured Optimus Prime facing certain doom against the Decepticons on a desert island. Magnus offers him the hand of friendship, but it is a ruse to allow Magnus to take the power of the Matrix, with an unexpected side-effect - the two brothers merge into Omega Prime and defeat their foes.

The Predacons and Decepticons attempt to turn Ultra Magnus to their side, but he refuses and channeling the power of the Matrix he and Prime now share, he supercharges the Autobot Brothers, giving them new powered-up forms. The discovery of a mysterious energy field radiating from beneath the Earth's surface leads both sides to the discovery of Fortress Maximus, a colossal Transformer city hidden on the planet to protect it. In the ensuing battles to claim its power, Dr. Onishi is accidentally set free by Sky-Byte. Now with Dr. Onishi advising them, the Autobots begin to put all the pieces together and, under his guidance, quickly locate all the O-Parts, which are combined to form a map that leads to the Orb of Sigma. In a failed attempt to acquire the orb, Megatron is buried in the ruins of a mysterious pyramid, but is resurrected by its energy as Galvatron. The Orb of Sigma soon leads the Autobots to Cerebros, the power key of Fortress Maximus, but he is stolen by the Decepticons and used by Scourge to activate Fortress Maximus, who rampages through the city until Koji calls out to him, and he stops. Experimentation soon makes it obvious that Maximus responds to human bio-signatures, leading the Decepticons to attempt to capture Koji (but accidentally snatching his friend Carl instead). With Maximus active, Scourge makes his power play, attempting to use him to destroy Galvatron, but when the scheme fails, all the Decepticons have their brains wiped. Galvatron proceeds to drain Fortruss Maximus's energy, boosting his already-formidable strength and then releases a swarm of cyber-bats across the Earth, using them to hold the children of the world to ransom to stay Optimus Prime's hand. Believing he has destroyed the Autobots in a lava flow, Galvatron then recalls his bats, but finds that his foes are still alive, leading to a final confrontation with Omega Prime at the Earth's core. The children of the world re-energize Fortress Maximus, who transmits his energy to Optimus Prime, forming the gigantic Matrix Blade, with which Prime finally defeats Galvatron. At the end, the Predacons and Decepticons—all but Sky-Byte—are imprisoned aboard Fortress Maximus and escorted by Ultra Magnus to Cybertronian space, and the remaining Autobots prepare to leave Earth for good after some rest and relaxation.