Jonathan Ecks, an FBI agent, realizes that he must join with his lifelong enemy, Agent Sever, a rogue DIA agent with whom he is in mortal combat, in order to defeat a common enemy. That enemy has developed a "micro-device" that can be injected into victims in order to kill them at will.
Leon, the top hit man in New York, has earned a rep as an effective "cleaner". But when his next-door neighbors are wiped out by a loose-cannon DEA agent, he becomes the unwilling custodian of 12-year-old Mathilda.
With computer genius Luther Stickell at his side and a beautiful thief on his mind, agent Ethan Hunt races across Australia and Spain to stop a former IMF agent from unleashing a genetically engineered biological weapon called Chimera.
An ex- CIA operative is brought back in on a very personal mission and finds himself pitted against his former pupil in a deadly game involving high level CIA officials and the Russian president-elect.
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 MIBs untarnished mission statement: protecting the earth from the scum of the universe.
Joe Enders is a gung-ho Marine assigned to protect a "windtalker" - one of several Navajo Indians who were used to relay messages during World War II because their spoken language was indecipherable to Japanese code breakers.