Parts: 1 (45-minute)
Writer: Neil Cross
Airdate: 20 April 2013
Production Code: n/a

Doctor: eleventh
Companions: Clara

Story: In stately old Caliburn House in 1974, professor Alec Palmer and empath Emma Grayling conduct parapsychological experiments in an attempt to prove the existence of a ghost that has been reported on the property since Anglo-Saxon times. Emma, able to sense the ghost's presence, is determined to help it cross over.. but both are surprised when an echoing knock on the front door turns out to be a summons not from beyond, but from the Doctor and Clara.

The Doctor has ulterior motives for coming to Caliburn House, but on arriving is caught up in the search for the ghost. As manifestations and spectral projections increase, the Doctor's investigation into the presence's identity could result in his death.