After two naked students, apparently making love at the time, fall to their deaths from a roof, Jonathan is driven to begin what he calls an "investigation" into who the students were and what led them to the rooftop.

As humanity picks up the pieces after the battle of Chicago, a shadowy group reveals itself in an attempt to control the direction of history…while an ancient, powerful new menace sets Earth in its crosshairs. With help from Cade Yeager, Optimus Prime and the Autobots rise to meet their most fearsome challenge yet.