Men in Black 3 (2012)

Agent J travels back in time to 1969 to prevent an alien, Boris the Animal, from killing his partner Agent K and altering history. With the help of a prescient alien, they acquire the ArcNet, a device that can save Earth from an invasion by the Boglodytes. They confront the younger and elder versions of Boris, and ultimately succeed in stopping the invasion and restoring the timeline.