Nine-year-old Tom Tomsky finds an ASG (Average Spooky Ghost) living in his basement. The green slime everywhere and loud noises are causing too much trouble for him. He reluctantly agrees to help the ASG get back his original home from an IRG (Incredibly Revolting Ghost). Professional Ghostbuster Hetty Camomile teaches Tom all about battling ghosts with graveyard dirt, mirrors, violet-scented perfume, raw eggs, and the color red. But the IRG's sweet tooth is the key to getting rid of him...