Optimus Prime and the Autobots investigate the return of the Decepticons while forced to account for a group of young humans who unwittingly become involved in their eons-old conflict.

When a weak life signal is received from Cliffjumper, the Autobots roll out and are met by newly-returned Megatron who has obtained a mysterious and powerful substance... Dark Energon!

Bulkhead is on a mission to rescue Agent Fowler, who has been kidnapped by the Decepticons. Complications arise when Miko secretly tags along.

Utilizing the Dark Energon, Megatron summons an army of undead warriors to battle Optimus, while the other Autobots launch a high-stakes rescue onboard the Decepticon warship.

The ultimate showdown unfolds in Earth's orbit as the Decepticons, aided by Megatron's undead army, do battle with the Autobots with the fate of the Earth hanging in the balance.

While Optimus Prime and Bumblebee square off against Skyquake, Starscream encounters challenges to his leadership at every turn.

Bulkhead, Bumblebee and Ratchet scramble to eliminate a swarm of Scraplets that have invaded Autobot base while Optimus and Arcee patrol in the Arctic.

Bulkhead eagerly anticipates a visit from his old friend Wheeljack, but when his buddy arrives things are not as they seem.

The Autobots assist Agent Fowler in transporting a hazardous explosive device, but this time they come under attack from more than just the Decepticons.

Miko and Bulkhead head to Greece on a field trip to recover an Energon Harvester; unfortunately, class is also in session for new Decepticons Knock Out and Breakdown.

Trying to impress a girl and get even with the school bully, Jack convinces Bumblebee to help him win a street race; but the action speeds out of control with the arrival of Knock Out.

Arcee takes Jack along on a seemingly routine mission, but encounters an archenemy and must face her deepest fears.

Optimus Prime becomes infected with a Decepticon plague, and Arcee and Bumblebee must sneak aboard the Decepticon warship to find the formula for the cure.

Megatron remains a fixture inside Bumblebee's mind and manipulates his actions back at Autobot base.

The kids accidently become stuck inside an alternate dimension during a GroundBridge malfunction. To make matters worse, they're trapped with a reanimated Skyquake!

The Autobots roll out to rescue Breakdown, the Decepticon, who has been abducted by Silas and the sinister agents of MECH.

Airachnid negotiates a deal with Silas to use MECH to exact revenge against Arcee and Jack.

Arcee and Bulkhead find their efforts to stop a Decepticon mission hampered by a magnetic device which forces them to work more closely together than usual.

The Autobots, with Jack and Miko, fall victim to an Energon mine cave-in and find themselves trapped with Starscream and Megatron!

Airachnid and Starscream are forced to partner to retrieve a powerful weapon; but upon being captured by Optimus and team, Starscream shockingly reveals that he would rather partner with the Autobots!