The Autobots discover that an Energon Harvester, an ancient and powerful device from Cybertron's distant past, is on display in a museum, and they attempt to retrieve it with Jack, Miko and Rafael's aid before it falls into the wrong hands. Starscream also learns of the Harvester's whereabouts, and he sends Soundwave, along with new Decepticons Knock Out and Breakdown, to obtain it.

Debuts: Knock Out and Breakdown

Jack accompanies Arcee on a routine scouting mission in a forest, where they discover a crashed space ship. They soon discover that the owner of the ship, the deadly and ruthless Decepticon sadist known as Airachnid, is still prowling the forest in search of a human to hunt, putting Jack in danger and causing Arcee to have visions regarding her last encounter with Airachnid on Cybertron during a mission with her partner; Tailgate

Debuts: Airachnid and Tailgate

Deaths: Tailgate