Reclusive Dr. Zorba has died and left his mansion to his nephew Cyrus and his family. They will need to search the house to find the doctor's fortune, but along with the property they have also inherited the occultist's collection of 13 ghosts.
Arthur and his two children, Kathy and Bobby, inherit his Uncle Cyrus's estate: a glass house that serves as a prison to 12 ghosts. When the family, accompanied by Bobby's Nanny and an attorney, enter the house they find themselves trapped inside an evil machine "designed by the devil and powered by the dead" to open the Eye of Hell. Aided by Dennis, a ghost hunter, and his rival Kalina, a ghost rights activist out to set the ghosts free, the group must do what they can to get out of the house alive.
Mystery Inc. withdraws from solving crimes after botching a case. When Vincent Van Ghoul contacts the gang about an unfinished investigation from Daphne, Shaggy and Scooby's past, the gang springs into action to finish the job that involves catching the 13th Ghost that escaped from the Chest of Demons and is still at large.
The 13 Ghosts of Scooby-Doo is the seventh incarnation of the Hanna-Barbera Saturday morning cartoon Scooby-Doo, and the final first-run version of the original 1969–86 broadcast run of the series. It premiered on September 7, 1985 and ran for one season on ABC as a half-hour program. Thirteen episodes of the show were made in 1985. It replaced Scary Scooby Funnies, a repackaging of earlier shows; another repackaged series, Scooby's Mystery Funhouse, followed. The series used to air in reruns on Cartoon Network, but now the series only airs from time to time on Cartoon Network's sister channel Boomerang.