The Doctor - Matt Smith
Clara - Jenna-Louise Coleman

Alec Palmer - Dougray Scott
Emma Grayling - Jessica Raine
Hila - Kemi-Bo Jacobs
The Crooked Man - Aidan Cook

Stunt Coordinators - Crispin Layfield, Gordon Seed
Stunt Performers - David Newton, Marcus Shakesheff, Tom Aitken

First Assistant Director - John Bennet
Second Assistant Director - James DeHaviland
Third Assistant Director - Heddi-Joy Taylor-Welch
Assistant Director - Daneille Richards
Location Manager - Nicky James
Unit Manager - Geraint Williams
Location Assistant - Iestyn Hampson-Jones
Production Manager - Phillipa Cole
Production Coordinator - Claire Hildred
Asst. Production Coordinator - Gabriella Ricci
Production Secretary - Sandra Cosfeld
Production Assistants - Rachel Vipond, Samantha Price
Asst. Production Accountants - Rhys Evans, Justine Wooff
Assistant Script Editor - John Phillips
Script Supervisor - Steve Walker
Camera Operator - Joe Russell
Focus Pullers - James Scott, Julius Ogden
Grip - Gary Norman
Camera Assistants - Meg De Koning, Sam Smithard, Evelina Norgren
Assistant Grip - Owen Charnley
Sound Maintenance Engineers - Ross Adams, Chris Goding
Gaffer - Mark Hutchings
Best Boy - Stephen Slocombe
Electricians - Bob Milton, Gareth Sheldon, Steve Guy
Supervising Art Director - Paul Spriggs
Set Decorator - Adrian Anscombe
Production Buyers - Charlie Lynam, Adrian Greenwood
Art Director - Amy Pickwoad
Standby Art Director - Helen Atherton
Assistant Art Director - Richard Hardy
Art Department Coordinator - Donna Shakesheff
Prop Master - Paul Smith
Prop Chargehand - Ian Griffin
Prophand - Austin J. Curtis
Standby Props - Rob Brandon
Dressing Props - Jayne Davies, Mike Elkins, Paul Barnett
Graphic Designer - Chris Lees
Graphic Artist - Christina Tom
Petty Cash Buyer - Florence Tasker
Standby Carpenter - Will Pope
Standby Rigger - Bryan Griffiths
Practical Electricial - Christian Davies
Props Makers - Penny Howarth, Alan Hardy, Jamie Thomas
Props Driver - Gareth Fox
Construction Manager - Terry Horle
Construction Chargehand - Dean Tucker
Scenic Artist - John Pinkerton
Assistant Costume Designer - Fraser Purfit
Costume Supervisor - Carly Griffith
Costume Assistants - Katarina Cappellazzi, Gemma Evans
Make-Up Artists - Sara Angharad, Julie Fox Pritchard
Casting Associate - Alice Purser
Assistant Editor - Becky Trotman
VFX Editor - Joel Skinner
Dubbing Mixer - Tim Ricketts
ADR Editor - Matthew Cox
Dialogue Editor - Darran Clement
Sound Effects Editor - Paul Jefferies
Foley Editor - Jamie Talbutt
Graphics - Peter Anderson Studio
Online Editor - Geraint Pari Huws
Colourist - Mick Vincent

With thanks to
The BBC National Orchestra of Wales
Conducted and orchestrated by Ben Foster
Mixed by Jake Jackson
Recorded by Gerry O' Riordan

Original Theme Music - Ron Grainer
Casting Director - Andy Pryor CDG
Production Executive - Julie Scott
Post Production Supervisor - Nerys Davies
Production Accountant - Jeff Dunn
Sound Recordist - Deian Llyr Humphreys
Costume Designer - Howard Burden
Make-Up Designer - Barbara Southcott
Music - Murray Gold
Visual Effects - The Mill
Special Effects - Real SFX
Prosthetics - Millennium FX
Editor - Nick Arthurs
Production Designer - Michael Pickwoad
Director of Photography - Mike Southon BSC
Script Producer - Denise Paul
Line Producer - Diana Barton

Executive Producers - Steven Moffat, Caroline Skinner

Clara and the Doctor arrive at Caliburn House, a haunted mansion sat alone on a desolate moor.

Within its walls, a ghost-hunting professor and a gifted psychic are searching for the Witch of the Well. Her apparition appears throughout the history of the building, but is she really a ghost? And what is chasing her?

"Caliburn House. Night four. November 25th, 1974. 11:04 pm."

Professor Alec Palmer and his assistant Emma Grayling are attempting to contact an apparition haunting Caliburn House. Emma is a psychic, and uses her gifts to gain the attention of the 'ghost'. They are interrupted by knocking at the front door, and open it to find the Doctor and Clara. The Doctor tells Alec that he is looking for a ghost and Clara claims that they are 'Ghostbusters'.

The Doctor claims to be from "the Ministry", and knows who Alec and Emma are. Photographs taken by the professor show the same figure in the same pose throughout the history of Caliburn House. The Doctor and Clara search the house, as a strange creature stalks them through it. Loud knocking is heard, which is said to be associated with the 'Witch of the Well'.

The Doctor takes a series of photographs of the 'ghost' throughout Earth's timeline. Clara believes that she is nothing more than a ghost to the Doctor, because as a time traveller he has been to a time when she is long dead. He tells her she is "the only mystery worth solving". The Doctor uses his photographs to explain that the 'ghost' is in fact a time traveller called Hila, who is trapped in a pocket universe and being chased by an unknown creature.

The Doctor uses a crystal from Metebelis III to enhance Emma's thoughts and use them to create a portal, a reality 'well'. He goes to rescue Hila, who escapes, but is trapped in the pocket universe with the monster. Clara returns to the TARDIS, and after a brief argument with the voice interface, manages to break into the pocket universe and rescue the Doctor from the creature.

In conversation with Emma, the Doctor reveals that he brought Clara to Caliburn house in order to see Emma, not the ghost. He asks what she senses about Clara, but Emma reports nothing unusual about her. As the Doctor and Clara are preparing to leave, the Doctor inadvertently reveals that Hila is Emma and Alec's future descendant. Alec and Emma are in love, and the Doctor advises them to "hold hands, and don't let go". Then the Doctor realises that the creature in the pocket universe has been trying to return to another creature in the house. He then states that every lonely monster needs a companion, and explains to Clara that the two creatures have been separated through time and space and certain events, and are yearning to be with one another. He describes this as not a "Ghost story" but a "Love story". He then returns to the pocket universe, where he reconciles with the monster to bring it back in the exact same manner as before.