Once allies, Optimus & Megatron are enemies in a civil war. To prevent Cybertron from falling into Megatron's hands, Optimus jettisons the planet's heart, the All Spark, into space, then sets out to find it with Megatron hot on his heels. Optimus is determined to defeat Megatron, bring the All Spark home, & restore Cybertron to its former glory.