Agents J (Will Smith) and K (Tommy Lee Jones) have seen some inexplicable things in Agent J's fourteen years with the Men In Black intelligence agency. When an alien assassin by the name of Boris the Animal (Jemaine Clement) escapes from the LunarMax prison, all bets are off. Time travel has been discovered and Boris tracks down the people who are responsible for creating it. Boris travels back in time to 1969 - the year that Agent K had shot off his arm and deployed a shield that led to Boris' race's extinction. As Agent J delves deep into the case, he soon finds himself travelling back to 1969. There, he meets the young Agent K (Josh Brolin) - who is every bit as awkward and demeaning as the elder Agent K is. J and K have their differences, but soon discovers that Boris has a much more sinister motive than originally thought. With the help of an alien super being named Griffin who can see into alternate realities, J and K begin a pursuit of Boris The Animal that takes them to Cape Canaveral, Florida just in time for the Apollo 11 launch. There, secrets that could change time and space forever are revealed