Prowl, Ratchet, Bumblebee, Optimus Prime, and other Autobots battle the Decepticons and search for the fragments of the AllSpark as Porter C. Powell continues to make a mess of things at Sumdac Systems, causing trash to pile up in Detroit.
The arrival of Ultra Magnus, Sentinel Prime, and Jazz are a welcome sight to Sari as she tries to hold her father's company together; but Porter C. Powell is determined to take over Sumdac Systems and reinstate Henry Masterson to head up military development.
Long thought lost, Megatron reappears with a new body and, as Megatron and the Deceptacons cause havoc, Optimus Prime is left to wonder if he and his Autobots are up to the challenge of keeping the AllSpark safe from evil.
Sari takes the Autobots for a tour of Detroit, where they encounter the Dinobots; and then the Autobots meet Nanosec, a villain who moves very, very fast--a little too fast.
The Transformers travel from deep space to New Detroit, where they face a new Decepticon threat and increased dangers as they try to protect the planet and themselves.
The S.U.V., the Society of Ultimate Villainy, makes a deal with arms-dealer-for-hire Swindle, and a prisoner who escaped from the Decepticons seems to be Bumblebee and he claims that Cybertronian is a double agent working for the Decepticons.
The Decipticons work to complete the construction of their space bridge, but in order to succeed in their task, Megatron will have to persuade an Autobot--Bulkhead--to help them.
Optimus Prime teams up with Dinobot Grimlock to stop Blackarachnia from working on her dangerous experiment with Meltdown; and later, Sari is left alone to defend the Autobots' home base from the Constructicons.
The Autobots struggle to overcome the mechanical turmoil caused by Megatron, prove their worth to the Detroit police force, and save the world from danger.
