Knock Out and Starscream experiment with synthetic lead and threaten to take over the Deceptacon ship and unleash an old enemy.

The Autobots go on alert as the Decepticons return to Earth in the series opener, Meanwhile a group of humans find themselves with new caretakers after stumbling into the middle of the Autobot conflict with the Decepticons.

Bulkhead acquires a top-secret formula, and the Decepticons come after him for it.

The Autobots go to the Earth's core to fight for the planet; and Jack uncovers info about Optimus' background.

The Autobots go in search of Cliffjumper, whose life signal is weak and find Megatron wielding the dangerous dark Energon.

Bulkhead is unknowingly shadowed by Miko as he goes to rescue Agent Fowler, who was kidnapped by the Decepticons.

The Autobots try to stave off an attack from Megatron's Terrorcons to protect their human wards.

The Decepticons and the Terrorcons go into battle against the Autobots.

Starscream pursues other interests while Skyquake battles with Optimus Prime and Bumblebee.

Scraplets invade HQ while Optimus and Arcee patrol the Arctic, leaving Bumblee and Ratchet to repel the enemy.

Bulkhead awaits a visit from his buddy Wheeljack, but his arrival does not go as planned.

The Autobots are attacked while helping Agent Fowler transport an implosion device.

Miko and Bulkhead go up against Starscream and Breakdown as they go to Greece to retrieve an Energon Harvester.

Jack tries to be impressive, with Bumblebee's help, but Knockout's arrivals sends things out of control.

Arcee must protect Jack when a routine mission is complicated by Airachnid's arrival.

A Decepticon plague infects Optimus Prime, so Arcee and Bumblebee sneak onto the Nemesis to find the cure.

Megatron controls Bumblebee from inside his mind and influences his behavior at HQ.

The kids are stranded with Skyquake in an alternate dimension during a GroundBridge malfunction.

MECH agents capture a Decepticon, and the Autobots mount a rescue.

Airachnid makes a deal with Silas to get revenge against Arcee and Jack.

The Autobots try to claim a magnetic weapon before the Decepticons get to it.

Two patrolling Autobots end up trapped in a cave with their enemies, Starscream and Megatron.

Starscream makes an unexpected request after he is captured by Optimus.

Ratchet becomes a threat to everyone after he injects himself with an experimental substance.

The Decepticons quickly try to build a space bridge before a prophesied darkness arrives.