K and J reunite to provide our best line of defence against a seductress who levels the toughest challenge yet to the MIBs mission statement: protecting the earth from the scum of the universe. While investigating a routine crime, J uncovers a plot masterminded by Serleena, a Kylothian monster who disguises herself as a lingerie model. When Serleena takes the MIB building hostage, there is only one person J can turn to -- his former MIB partner.
