Optimus teams up with Sentinel Prime in order to defeat the Headmaster.

Unaware of the Decepticon activity, the Elite Guard take Optimus Prime and the Autobots back to Cybertron.

When the AllSpark turns construction vehicles into Autobots, Bulkhead becomes fast friends. However, the Decepticons have other plans in mind.

The second-rate villains of Detroit team up to beat the Autobots.

While chasing an Autobot traitor, Bumblebee thinks back on the time he spent with Bulkhead in the Autobot Boot Camp.

The Autobots must rally to prevent the AllSpark from falling into the clutches of the Decepticons.

Starscream, Lugnut and Blitzwing invade Earth; Optimus Prime makes Sari turn over her Allspark key.

Blackarachnia confronts Bumblebee and Bulkhead as they are celebrating their first Halloween.

Blitzwing and Lugnut come to Earth to help Megatron get the Allspark.

Ratchet's old enemy, the bounty hunter Lockdown, resurfaces.

Optimus Prime and his band of Autobots are taken off the job when the Cybertron Elite Guard, led by Ultra Magnus, comes to Earth looking for the AllSpark.

The AllSpark creates a new Autobot out of pieces of garbage.

Bumblebee competes against the Decepticons in an underground racing competition.

Prowl and a mysterious Decepticon bounty hunter go after Starscream.

Unlikely matchups! It's Optimus Prime and Dinobot Grimlock vs. Blackarachnia and Meltdown.

Sari has to defend the Autobot home base from invading Constructicons.

Starscream captures Bumblebee and a number of civilians in an attempt to obtain the Allspark.

Bulkhead is suspicious of the musical robot player Sari receives as a birthday gift.

The Autobots find the Allspark and the Decepticons try to seize it.

Megatron reprograms Professor Sumdac's animatronic dinosaurs, turning them into Dinobots.

When Sari mysteriously disappears, Prowl and Bulkhead go searching for her on Dinobot Island.

Prowl, Bumblebee, and Sari investigate a Cybertronian energy signal detected by Optimus Prime.

The battle continues; Sari Sumdac discovers the Autobots and the Allspark.

The Autobots find that their new base on Earth is already inhabited.

Bumblebee springs into action when Megatron unleashes a speed demon and sends it on a crime spree.