University parapsychologists Dr. Peter Venkman (Bill Murray), Dr. Raymond Stanz (Dan Aykroyd) and Dr. Egon Spengler (Harold Ramis) lose a research grant when their experiment methodology is proven to be bogus. The team decides to go into business for themselves and open 'Ghostbusters,' a ghost removal service. After struggling to get on their feet, they are summoned to investigate the strange happenings in Dana Barrett's (Sigourney Weaver) Central Park West apartment. What they discover is that all Manhattan is being besieged by ghosts and other worldly demons through a portal in her building.