When a narcotics team sent to bust some drug dealers are massacred. The police department form a special unit of undercover cops whose identities are withheld from the brass, and are only accountable to the leader, a Lieutenant. While they try to bust the dealers, the Lieutenant tries to find out who gave the dealers the information about the bust. And he suspects that it's someone in the DEA.
In the opening chase, Martin Riggs and Roger Murtaugh stumble across a trunk full of Krugerrands. They follow the trail to a South African diplomat who's using his immunity to conceal a smuggling operation.
Five years after they defeated Zuul, the Ghostbusters are out of business. When Dana begins to have ghost problems again, the boys come out of retirement to aid her and hopefully save New York City from a new paranormal threat.