Optimus Prime is then informed that Megatron has infected the core of Cybertron with dark energon and is given the task to undo the damage done. After rescuing , Optimus, Ironhide, and Prowl fight their way to the core, but it's too late. The core informs Optimus that it is far too corrupted. It can repair itself by shutting down, but it will take millions of years. By that time, Cybertron will have to become cold, barren, and uninhabitable. The core gives Optimus a small piece of itself, saying it will still survive as long as the piece does. Optimus accepts the burden and the core relinquishes the Autobot Matrix of Leadership.