Autobots and Decepticons are at war, with humans on the sidelines. Optimus Prime is gone. The key to saving our future lies buried in the secrets of the past, in the hidden history of Transformers on Earth.

The Autobots continue to work for NEST, now no longer in secret. But after discovering a strange artifact during a mission in Chernobyl, it becomes apparent to Optimus Prime that the United States government has been less than forthright with them.