Transformers: Animated - Season 1 (2007)

Optimus Prime and the Autobots set up base at an old auto-parts shop. Meanwhile, Megatron's head comes back online and takes control of several robots to attack the Autobots and reclaim the AllSpark.

A scientist named Prometheus Black has a lab accident that turns him into Meltdown, a super villain secreting acid that melts anything. He goes after revenge against Sumdac and the Autobots.

Professor Sumdac's latest creations begin to think for themselves. Eventually, these Dinobots start to hunt down the Autobots.

While Autobots encounter a mysterious muscle car creating havoc in Detroit, Ratchet keeps flashing back to his time in the Great War.

Megatron continues to try and persuade Dr Sumdac to rebuild his body. A key component is Destronium, but given its instability, the nearest source would need to be transported quickly. Using a thief and an experimental speed-suit from Sumdac's facilities, Megatron may get what he needs, unless the Autobots can stop the speedy thief.

Bumblebee and Bulkhead are having fun celebrating their first-ever Halloween with Sari. That is, until the Decepticon Blackarachnia shows up to ruin their good times.

Continuing to use Dr Sumdac's naiveté to find a way to have a new body, Megatron helps the Doctor create a music-playing robot for Sari's Birthday, named Soundwave.

Blitzwing and Lugnut arrive on Earth, tracking a mysterious signal.

Meltdown kidnaps Sari to experiment on her and get revenge against her father.

One of Sumdac's ex-workers takes control of an Autobot. He then takes the Autobot out on the town.

Prowl, Bumblebee and Sari head into the forest to find the source of mysterious Cybertronian energy readings.

When Starscream, Lugnut and Blitzwing begin their invasion of Earth, Optimus Prime demands Sari hand over her key for safekeeping. This causes her to run away, only to end up in the clutches of Blackarachnia. Optimus begins to doubt his leadership even when the next stage of Megatron's plot to be rebuilt begins.

The Autobots are beaten down by the Decepticon invasion, but still rally to keep the AllSpark from their clutches.