A struggling inventor named Cade Yeager (Mark Wahlberg) works out of his Texas shed and home, trying to make ends meet by repairing odds and ends for neighbors and hoping to strike it rich with the next big robotics invention. He's also doing what he can to watch out for his seventeen year old daughter Tessa (Nicola Peltz) whose college education depends on the family's nonexistent finances. Cade one day purchases a rusty, beat-down truck and, while attempting repairs, is surprised to discover that it's actually Optimus Prime (voiced by Peter Cullen), leader of the Autobots who has effectively been exiled from humanity. The world is still reeling from the destruction the Transformers have caused, particularly in the city of Chicago, and there is a bounty out for their heads. Cade's friend Lucas (T. J. Miller) would rather turn the Transformer in, and a phone call yields the arrival of a government spook squad out to retrieve the national security "threat" without a warrant. Cade, his daughter, and Lucas barely escape thanks to the driving skills of Tessa's boyfriend Shane (Jack Reynor). The foursome, plus Prime, finds itself on the run from the government and its secret collaborator, a sleek bounty hunting Transformer named Lockdown (voiced by Mark Ryan). Meanwhile, a successful robotics entrepreneur named Joshua Joyce (Stanley Tucci) is inventing his own Transformers, including the speedy Stinger and the mighty Galvatron (voiced by Frank Welker).