As the Autobots try to capture a mysterious muscle-car causing havoc all over Detroit, Ratchet starts experiencing flashbacks of his past, from the War for Cybertron, when he was captured and held prisoner by a Decepticon bounty hunter named LOCKDOWN. This starts to affect Ratchet's performance in the field, but he refuses to talk about it, until Optimus Prime is captured by the muscle car... which transforms into Lockdown! The bounty hunter reveals that he created the mayhem to draw the Autobots out so he could capture Prime for the Decepticon bounty on his head. When the Autobots come to rescue Prime, Lockdown defeats them one-by-one, planning to remove their best parts to "upgrade" himself... until Ratchet finds the courage to face his former captor and free his friends.
—Andrew Robinson