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.

汽车人和霸天虎的战斗绵亘了几个世纪都未曾结束，而他们的后代——巨无霸和原始兽，更将新一轮的战斗推向了史前时代。在寻找新能源的途中，霸王龙（David Kaye 配音）指挥原始兽通过时空跳跃来到史前地球，而巨无霸也在擎天圣（Garry Chalk 配音）的带领下尾随而至。双方的拉锯战仍在继续，不久连早已盘踞在该星球的外星人沃克人也卷入其中。而穿越时空者身上承载的未来的信息，让外星人大为惊恐，由此使得战斗更加激烈。在此之后，霸王龙发现了汽车人留在地球的战舰方舟号，为了改变霸天虎战败的历史，他们试图摧毁处在沉睡中的擎天柱。 攸关全宇宙命运的战斗，在远古时代提前拉开了序幕……

As humanity picks up the pieces, following the conclusion of "Transformers: Dark of the Moon," Autobots and Decepticons have all but vanished from the face of the planet. However, a group of powerful, ingenious businessman and scientists attempt to learn from past Transformer incursions and push the boundaries of technology beyond what they can control - all while an ancient, powerful Transformer menace sets Earth in his cross-hairs.

On their home planet of Cybertron, the Autobots and Decepticons are involved in an explosive battle over the coveted AllSpark. With the fate of the universe at stake, the Autobots send it far from the reaches of the ruthless Megatron, leader of the Decepticons. But there are even more surprises in store when it crash-lands on Earth.