"The Unquiet Dead" is the third episode of the first series of the British science-fiction television programme Doctor Who, first broadcast on 9 April 2005 on BBC One.

The Doctor and Rose team up with Charles Dickens (Simon Callow) to investigate Mr Sneed (Alan David), a man who runs a funeral parlour where it seems that corpses have come to life.

It is revealed that the gaseous Gelth (voiced by Zoe Thorne) have entered Cardiff through a Rift, and wish to survive by taking over the corpses.

Callow, who had researched Dickens as well as portraying him on multiple occasions, accepted the guest starring role in "The Unquiet Dead" because he felt the historical figure was written accurately.

This episode's mention of the Series wide arc, "Bad Wolf," comes in a conversation between Rose and Myles' character, Gwyneth.

At a nearby funeral parlour, run by Gabriel Sneed and his servant Gwyneth, the corpse of the late Mrs. Peace has been taken over by a blue vapour.

The blue vapours fill the room and reveal that they are the Gelth, a once-corporeal alien race until they were devastated by the Time War.

The Doctor offers the Gelth temporary use of the corpses until he can transport them to a place where they can build new bodies, using Gwyneth as a bridge to cross the rift.

The Gelth deceived how many of them there are, and their true motive is revealed: they intend to kill the living to give themselves more hosts and take over the planet.

As the third episode of the revived series, it was designed to continue to show the range of the programme by exploring the past, after the contemporary "Rose" and far-future "The End of the World".

[3] Gatiss originally resisted having Dickens star in the episode, as traditionally the Doctor only mentioned meeting historical figures, but he eventually warmed to the idea.

[3] In one scene, Gatiss wanted the knocker on a door behind Dickens to briefly show the Gelth's face in reference to A Christmas Carol, but this visual effect was not done.

[3] Davies requested a scene in which the Doctor takes Rose to the future to see a world filled with walking corpses — the result if they had left before defeating the Gelth — but this was too expensive to film.

[3] Simon Callow, who portrayed Dickens, was considered apt since he possessed extensive knowledge of the author and had experience playing the character and recreating his public readings.

[9] After inadvertently attending the audition in a T-shirt emblazoned with an image of two naked women kissing under the slogan "I support Nudist Colonies", Myles was convinced she had not got the part; her appearance contrasted grossly with Gwyneth's personality.

After being notified of her success Myles did not want to prioritise between her theatre commitments and Doctor Who; her agent decided that she would appear in the episode.

[9] Russell T Davies was enamoured by her performance, which he felt confirmed that the actress was "one of Wales's best-kept secrets", and subsequently wrote her a lead role in the Doctor Who spin-off Torchwood.

[18] Based on research of Victorian morgues, the production team selected red and sepia as the main colour scheme.

[3] The actors who played the dead bodies possessed by the Gelth had simple make-up, with just shading and contact lenses and no prosthetics.

He criticised the script for promoting xenophobia and "claiming that all foreigners were invaders",[26] especially as the top stories in the news were about immigration into Britain.

[30] Charlie Brooker of The Guardian wrote that the episode "may be the single best piece of family-oriented entertainment BBC has broadcast in its entire history", complimenting that "it's clever, it's funny, it's exciting, it's moving, [...] it looks fantastic, and in places it's genuinely frightening".

[31] Now Playing magazine reviewer Arnold T Blumburg gave "The Unquiet Dead" a grade of A−, describing it as "spectacular", though he noted there were "a few hiccups, such as the weak and convenient plot point that forces the Gelth ... to be drawn out of their human hosts by the mere presence of gas".

[32] In 2013, Mark Braxton of Radio Times described the episode as "a sparkling script, as crisp and inviting as a winter wonderland", praising the magical atmosphere and the treatment of Dickens.

[34] Despite this, he wrote that the story was still enjoyable, with a "delightfully ludicrous" set-up, "vividly realized" period setting, and the characterisation of Dickens.