The Old Book of Magic is a large hardcover book about magic, procedures, rites, and unresolved mysteries.
Jenny Moran started research on an entity the Ghostbusters encountered in the City Water Tunnel No. 3. Going on the fact it had a head shaped like a pumpkin and an Irish accent, Jenny focused on a ghost that manifested during the festival of Samhain. Ray consulted the Old Book of Magic and learned the ghost wasn't seen in centuries and was believed to have been banished by a druid that learned its real name. Ray remembered the druids didn't have a tradition of writing so the ghost's real name was lost.
- "The Old Book of Magic" is an actual book printed in 1918 and it was written by Lauron William De Lawrence. It was a precise history of magic, its procedure, rites, and mysteries contained in ancient manuscripts and embellished engravings of charms and talismans.