While searching for clues to their missing memories, Blackarachnia and Rattrap encounter Jetstorm, Thrust, and Tankor -- three deadly new Vehicon generals created by Megatron.

Rattrap finally learns how to transform, only to discover his Robot Mode has no weapons. With nowhere else to turn for protection, he strikes a deal with Megatron.

Megatron sends his generals and Diagnostic Drone into the catacombs to kidnap Nightscream and learn the secret behind his Beast Mode. Nightscream is forced to relive a painful memory from his past.

Tankor uncovers an ancient weapon with the power to turn organic material into cybernetic metal. Nightscream gets hit by the weapon, and the Maximals race against time to save him from going offline.

Rattrap uncovers a catalyst program that accelerates the growth of Cybertron's newfound plant life. Meanwhile, Blackarachnia discovers the truth about Thrust's Spark.

Megatron prepares a doomsday weapon that can wipe out everything organic on Cybertron -- including the Maximals. Meanwhile, Optimus discovers his own doomsday weapon...