Ghostbusters

Ghostbusters was a film about an organisation that fought ghosts.

When Graham Stevens told Ace that he was of Paranormal Investigations, Ace asked if he meant like Ghostbusters. (PROSE: Cat's Cradle: Witch Mark)

When investigating the Ghost Shifts, the Tenth Doctor referenced the theme song when he brought out a device to track them, asking Rose, "Who you gonna call?", to which she replied, "Ghostbusters!" (TV: Army of Ghosts)

In Ashen Hill Manor, Clyde Langer wished he had a Proton Pack from the movie while trying to find a ghostly entity. He also said, "I ain't afraid of no ghost", part of the Ghostbusters' theme tune. (TV: The Eternity Trap)

Clara Oswald introduced the Eleventh Doctor and herself to Emma Grayling and Alec Palmer as "Ghostbusters". (TV: Hide)

Cass referred to the Twelfth Doctor and Clara Oswald as "ghostbusters". (TV: Under the Lake)

Behind the scenes

 * During the Army of Ghosts scene, the musical soundtrack subtly references the Ghostbusters theme.
 * In part two of Death of the Doctor, the sound effect used during the activation of the memory weave is the same sound effect used in the Ghostbusters movies, cartoons, and video games for powering up a Proton Pack.
 * Ernie Hudson was one of the stars of the film.