The Battle for Cybertron is a book-and-cassette story.
War rages on the planet Cybertron between the heroic Autobots and the evil Decepticons. The fighting's become so intense that Cybertron has been ripped from its orbit and is hurtling through space out of control. Optimus Prime gathers his forces aboard the Ark and leaves to clear a path through an asteroid belt, but the Decepticons discover their ship and attack. The ship crashes into a mountain on Earth, "sending the mighty dinosaurs running in terror."
Millions of years later a volcanic eruption awakens the Ark's computer, which begins repairing the robots aboard so they can transform into machinery it detects on Earth. However, it's too damaged to tell the Autobots and Decepticons apart, and finishes the Decepticons first. They fly outside and attempt to blow up the ship, but their energy is too low to break through the force field and they fly off to repower themselves.
Sparkplug and Spike, who witnessed the attack, meet Bumblebee. Apparently the attack damaged the Ark's computer before it could finish reviving the rest of the Autobots, and Sparkplug finishes the job for it. Optimus tells Hound to take their new friends home, but on the way they see the Decepticons attack a power station and drain all the energy, prompting them to return and warn Optimus. He decides to have the Autobots leave the ship and set a trap for their enemies while the computer defends the ship. While the Autobots catch the first wave of the Decepticons' strike force by surprise, another wave comes from the opposite direction and Starscream takes out Optimus with his null ray. The Autobots start to panic without their leader, but Sparkplug manages to reactivate Prime. Their energy running low again, Megatron calls a retreat...for now.