It is about people stopping bad aliens and it is miles better than "Men in Black II" and "Ghostbusters II" which it is a combination of. Some weak improvisation and jokes don't work, but at least I liked a couple of the scenes.
This is one hilarious fucking movie. These actors are just playing their best selves and having a great time doing it. Agent Moulder, with the Seven Up guy, Stifler, and Jeff Goldblum's girlfriens in The Lost World.