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.