After the battle of Chicago (TRANSFORMERS: DARK SIDE OF THE MOON) the robot aliens are on mankind's shit list. Some of the good Autobots have been offered protection but there's human bounty hunters, working for a new type of Transformer, that are hunting down all the transformers on earth. There's a company that's able to create their own intelligent robots an they want al the original ones to be gone.
Cade Yeager (Mark Wahlberg) is a small-time robotics designer/mechanic who purchases an old truck, which happens to be the injured Optimus Prime. The bounty hunters track them down to his farmhouse and nearly kill them--but they all get away. This includes Yeager's daughter, Tessa (Nicola Petz of BATES MOTEL) and her boyfriend, Shane. The rest of the movie is them stopping the evil company and also saving the Autobots. Along the way we find out that the Transformers were responsible for the extinction of the dinosaurs.
AGE OF EXTINCTION is better than the last two TRANSFORMERS movies, basically re-booting the franchise to make it more gritty and give it a fresh spin. It's by far the best TRANSFORMERS sequel.