At a funeral home in Cardiff in 1869, Mr Sneed offers his condolences to Redpath upon the death of his grandmother. He assures the grandson that she's merely asleep, not death. Redpath asks for a moment alone but then looks on in horror as his grandmother Mrs Peace's corpse comes to life and starts choking him. Sneed hears the commotion and comes back in, and realizes they have another one. He calls for Gwyneth, the maid, but the corpse knocks him down and snaps Redpath's neck, and then breaks open its coffin and walks out into the winter night, screaming as energy flows from it.
The Doctor navigates the TARDIS through time to London 1860.
When Sneed wakes up, he calls for Gwyneth, who finally arrives. He informs her that Redpath's grandmother is risen from the dead and has killed her grandson. Gwyneth isn't surprised but the news, but is shocked that Sneed lets the situation continue. She warns that something terrible is happening and they need to get help, and Sneed tells her they'll deal with it once they recover the grandmother.
The TARDIS makes its way to Cardiff and the Doctor has Rose dress in period garb to avoid drawing attention.
Sneed and Gwyneth ride the streets in the funeral home's hearse but are unable to find a trace of the grandmother. When they fail, Sneed tells Gwyneth to use her "sight" to find the old lady, or he'll fire her. She reluctantly does so and confirms that Mrs Peace had a desire to see a great man who had come all the way from London.
At the Taliesin Lodge, the stage manager comes to see their featured performer: Mr. Charles Dickens. He is brooding about being alone, and admits he's been clumsy in family affairs. The stage manage wonders if he thinks things are finished, but Dickens explains that he will simply go on and on, and his imagination grows stale. However, he braces himself and goes out on stage.
Once Rose is properly dressed, she steps out the doors and enters the past for the first time.
The audience applauds as Dickens emerges on stage. he's unaware that Grandmother Redpath is in the audience.
Gwyneth leads Sneed to Taliesin Lodge, while nearby, the Doctor confirms that they're in Cardiff in 1869 and missed their target by nine years. Rose doesn't care.
Dickens reads from A Christmas Carol
, but stares in horror as a glowing gas flows from Grandmother Redpath. The gas spreads out and she screams. Outside, the Doctor hears the sound and immediately cheers up. He runs into the lodge to investigate as the audience panics despite Dickens' attempts to calm them. Sneed and Gwyneth come in as the gas assumes ghostly figures that float around the auditorium. As the Doctor arrives, Grandmother Redpath collapses and Sneed and Gwyneth grab her and haul her out. Dickens assumes that the Doctor is responsible, while Rose spots the fleeing couple and goes after them. The Doctor interrogates Dickens about the corpse.
Outside, Rose realizes that Grandmother Redpath is dead. Sneed chloroforms her and piles her into the hearse.
The Doctor realizes that the substance is a gas and watches as it flows into the gaslights. He runs outside and sees Sneed and Gwyneth escaping in their hearse. The doctor takes Dickens' coach and follows them, and Dickens insists on following. The Doctor is surprised and pleased to realize he's traveling with the famous author, and explains that Rose is in danger. When he realizes the danger, Dickens gets into the thrill of the chase.
Sneed and Gwyneth take the unconscious Rose to one of the viewing rooms and leave her, unaware that the gaslights are flickering. They consider what to do when they hear a knock on the door. Sneed sends Gwyneth to answer it. Meanwhile, Rose wakes up, unaware that the gas is flowing into the dead Redpath, reanimating him.
At the door, Dickens demands to see Sneed and won't accept Gwyneth's denials. The gas lights flicker behind the maid, and the Doctor realizes something is going on.
The reanimated Redpath approaches Rose and he tries to get out, only to discover the door is locked.
The Doctor bursts in and realizes that something is inside the gas pipes.
Grandmother Redpath reanimates as well and they both advance on Rose. The Doctor hears her screams and kicks in the doors. He pulls Rose free and asks the creatures what they want. They say that they need him to open the Rift, and they're dying. The gas then leaves the corpses and they collapse.
As Gwyneth serves tea, Rose demands an explanation and Sneed explains that the house always had a reputation for being haunted. However, he never experienced anything until three months ago when the corpses started coming to life. When they come to life, they hang onto aspects of their old life. Dickens insists it's just an illusion and the Doctor tells him to shut upif he has nothing to contribute. When Sneed admits that the gaslight flickers are new, the Doctor realizes that the Rift is growing larger. Meanwhile, dickens goes out to investigate the gaslights and then check Redpath's corpse. He confirms that Redpath is dead while the Doctor comes and insists that what he saw is real. The Doctor explains that the human body breaks down and emits gasses, making corpses the perfect host. Dickens wonders if he has wasted his time working for social good and dismissing fantasists, when ghosts and other such creatures really exist.
Rose helps Gwyneth in her chores and the two women discuss their education and shopping. The talk turns to boys and Gwyneth admits that Rose is much less sophisticated than she appears. The maid insists that Sneed was kind to take her in after her parents died, and she expects to be reunited with them in Heaven. When Gwyneth notes that Rose may be reunited with her dead father, Rose wonders how she knew. Gwyneth reluctantly admits that she has an ability and describes Rose's time, and mentions the "big bad wolf." She then snaps out of her trance, shocked, The Doctor comes in, overhears what she says, and realizes that her gift of sight is growing stronger. he explains that she's the key since she grew up on the Rift, and her power is growing as it grows larger. He says that he needs her help to conduct a séance.
Gwyneth leads them in the séance, but Dickens objects, insisting it's all a trick. The Doctor convinces him to stay and Gwyneth begins. The lights flicker and Gwyneth goes into a trance. Glowing gas enters the room and they hear voices chanting. The Doctor tells Gwyneth to control them and let them through her. Figures appear through her and identify themselves as the Gelth, and ask the Doctor to take Gwyneth to the Rift to make a bridge. The aliens explain that when the Time War happened, all but a few of their race were destroyed. Now they use abandoned human corpses to give them a physical form. When Rose objects, the Doctor notes that it could save the aliens' lives. As the Gelth disappear, Dickens is shocked, realizing that it's all true.
Afterward, Rose treats Gwyneth while the Doctor insists that the Gelth need her help. Rose refuses to let him bully Gwyneth into helping. The Doctor explains that the Gelth have been trying to get through the Rift, but they're weak and eventually revert to gas and hide in the pipes. He insists that Gwyneth give the Gelth a foothold, but Rose refuses to countenance it. She objects to it, but the Doctor tells her to get used to a different morality. Gwyneth asks if she gets a say, and Rose say she doesn't understand. The maid realizes that Rose thinks she's stupid, and she insists that the "angels" need her. Gwyneth believes her mother sent them, and the Doctor explains they need to find the Rift. He has Sneed confirm that the ghosts are seen primarily in the morgue.
As Rose and the Doctor search the morgue, she wonders how the Gelth can be reborn if they are not in her time. He explains that time can be rewritten and nothing is safe. Dickens notices that the room is getting colder, and the Gelth appear before them and ask for their pity and help. The Doctor promises to take them somewhere so they can build permanent bodies. The Gelth directs Gwyneth to the arch and instruct her to reach out into the void. They establish a bridgehead and Gwyneth calls out to them. Gas emerges from her and the Gelth turn into sinister glowing forces. They reveal that their are millions of them, and occupy the corpses in the morgue. When Sneed tries to stop Gwyneth, one of the animated corpses snaps his neck and another Gelth enters his body. The corpses advance on Rose and the Doctor, and the Doctor tells Gwyneth to send them back. Dickens runs in terror while the Doctor and Rose lock themselves behind a gate.
Upstairs, Dickens gets out of the house but watches as the Gelth leave the house and spread out through the streets. He notices them enter the gaslights and realizes what the Gelth's weakness is. He runs back into the house and turns off the flames.
In the morgue, Rose wonders how she can die before she's ever born, but the Doctor apologizes and explains that time can be twisted into any shape. They take hands and the Doctor admits that he's glad he met her. Dickens runs back and starts snuffing the flames, and the Doctor realizes that filling the room with gas will draw the Gelth out of the corpses. The Gelth corpses advance on Dickens but then leave the bodies. The Doctor tells Gwyneth to send the aliens back, and she realizes that the "angels" lied to her, and that her parents would say the same. Gwyneth warns that she's not strong enough to send them back, but she can hold them. She takes a box of matches out of her pocket. Rose objects but the Doctor promises he won't let Gwyneth endanger herself and has Dickens get her out.
The Doctor looks at Gwyneth for a moment, and then kisses her on the forehead and thanks her. He runs out as she takes out the matches and lights one, igniting the gas. The funeral home blows up just as the Doctor gets out. Rose looks at him in shock and he admits that he's sorry. However, he explains that Gwyneth was dead the minute she stepped into the archway. When Rose wonders how she could have talked to them and ultimately sacrificed her life, Dickens says that there are some things that even the Doctor can't know.
As they return to the TARDIS, Rose wonders what Dickens will do now. The author says that he will return to London, spend time with his family, and make amends for his actions. He is enthused with his inspirations, and promises to incorporate what he's seen into his newest novels. The Doctor wishes him luck and they start to enter into the TARDIS. However, Dickens asks him for one last bit of future knowledge: will his books last? The Doctor assures them that they will last forever.
Inside, the Doctor and Rose watch Dickens and the Doctor assures her that in a week Dickens will be dead and unable to include knowledge of the Gelth in his works. The author watches as the TARDIS disappears. Laughing, Dickens walks down the streets and says, "God bless us, everyone!"