Strange phenomena surface around the globe. The skies ignite. Terror races through the world's major cities. As these extraordinary events unfold, it becomes increasingly clear that a force of incredible magnitude has arrived. Its mission: total annihilation over the Fourth of July weekend. The last hope to stop the destruction is an unlikely group of people united by fate and unimaginable circumstances.

James, an NYC cop, is hired by Agent K of a secret government agency that monitors extraterrestrial life on Earth. Together, they must recover an item that has been stolen by an intergalactic villain.

Kay and Jay reunite to provide our best, last and only line of defense against a sinister seductress who levels the toughest challenge yet to the MIB's untarnished mission statement – protecting Earth from the scum of the universe. It's been four years since the alien-seeking agents averted an intergalactic disaster of epic proportions. Now it's a race against the clock as Jay must convince Kay – who not only has absolutely no memory of his time spent with the MIB, but is also the only living person left with the expertise to save the galaxy – to reunite with the MIB before the earth submits to ultimate destruction.