Boris the Animal (Jemaine Clement), last of the Boglodite race, escapes from lunar prison. He wants vengeance on Agent K (Tommy Lee Jones), who shot off his left arm and jailed him. Boris flees from K and his partner Agent J (Will Smith), telling K that he is "already dead." K refuses to reveal details of his past with Boris, so J searches the MIB database. J finds murders by Boris, and that K deployed an 'ArcNet' in July 1969 that protected Earth from invading Boglodites, thus starving them to extinction. More details are classified, and Agent O (Emma Thompson), Chief Zed's replacement, stonewalls J with the same answer as K. That night, K vanishes, and only J remembers. O shows J a statue to K, killed by Boris in 1969. J learns his chocolate milk craving is a result of a 'temporal fractu