In Men in Black™ 3, Agents J (Will Smith) and K (Tommy Lee Jones)
are back... in time. J has seen some inexplicable things in his 15
years with the Men in Black, but nothing, not even aliens, perplexes him
as much as his wry, reticent partner. But when K's life and the fate of
the planet are put at stake, Agent J will have to travel back in time
to put things right. J discovers that there are secrets to the universe
that K never told him -- secrets that will reveal themselves as he teams
up with the young Agent K (Josh Brolin) to save his partner, the
agency, and the future of humankind.