When the discovery of an ancient artifact unleashes an evil force, Ghostbusters new and old must join forces to protect their home and save the world from a second Ice Age.

Three scientists, who specialize in studying the paranormal, start a business of capturing and containing ghosts in New York City. As their business grows, they face a major supernatural threat that could bring about the end of the world.

When a single mom and her two kids arrive in a small town, they begin to discover their connection to the original Ghostbusters and the secret legacy their grandfather left behind. As they explore their grandfather's farmhouse, they find his ghost traps and uncover a portal to the evil dead in a nearby mine shaft. With the help of their new friends, they must use their grandfather's ghostbusting equipment to capture the ghosts and stop an ancient evil from being resurrected. Along the way, they reconcile with their grandfather and join forces with the original Ghostbusters to save the town and the world.

The Ghostbusters are sued and barred from investigating the supernatural. They must find a way to stop the spirit of Vigo the Carpathian from possessing a child and returning to life. Along the way, they uncover a river of pink slime that reacts to emotions. They use positively-charged mood slime and the Statue of Liberty to defeat Vigo and save New York City.