s 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.

Overview from themoviedb.org