Paranormal researcher Abby Yates (Melissa McCarthy) and physicist Erin Gilbert (Kristen Wiig) are in the midst of proving the existence of paranormal phenomena such as ghosts, in modern society. When strange apparitions appear in Manhattan, Gilbert and Yates turn to engineer Jillian Holtzmann (Kate McKinnon) for help. After witnessing a ghost in a subway line, lifelong New Yorker Patty Tolan (Leslie Jones) also joins the team as the group undertakes an investigation to stop the otherworldly threat.
Armed with proton packs and plenty of attitude, the four women band together and answer the call for an epic battle as more than 1,000 mischievous ghouls descend on Times Square.