The Men in Black are back, and this time Agent J (Will Smith) must take a trip into the past in order to save both the future and his taciturn partner Agent K (Tommy Lee Jones) in the third installment of the hit sci-fi comedy series. After 15 years of working with aliens from all across the cosmos, Agent J is sure he's seen it all. But just when he's getting the hang of the game, he learns that history has inexplicably been rewritten. In this new timeline of events, Agent K has been dead for 40 years, and Earth will soon come under attack from an extraterrestrial force with the power to claim the entire planet. Now, in order to set the past straight and head off an invasion of epic proportions, Agent J must travel back to the year 1969, when Young Agent K (Josh Brolin) was just a fresh new face on the force. But Agent J only has 24 hours to find the source of the coming catastrophe and discern how his longtime partner ties into the situation -- should he fail he'll be stuck in the past forever.