[[quoteright:350:http://static.tvtropes.org/pmwiki/pub/images/ghost_light_1280.jpg]]
[[caption-width-right:350:Man, Series/DowntonAbbey got ''weirrrrd''...]]
->'''Gwendoline:''' I think Mr. Matthews is confused.
-> '''The Doctor:''' Never mind, I'll have him completely bewildered by the time I'm finished.

To make a long story as short as humanly possible, the Doctor takes companion Ace back in time to the Victorian era for some form of training that involves facing her childhood fears. The TARDIS lands in a mansion of the era, and the Doctor and Ace soon find themselves the guests of a "Josiah Smith" who proudly proclaims the wonders of the Darwin concept of evolution. Ace, who has a trauma involving haunted mansions, tells the Doctor that she doesn't appreciate his lesson. Also, there is a Rev. Ernest Matthews, who despises evolution, there's a maid service that refuses to stay in the house after 6pm... and a polite, well-dressed Neanderthal butler named Nimrod. The maid service is apparently also taking care of GreatWhiteHunter named Redvers Fenn-Cooper, who has recently lost his mind by "[[GoMadFromTheRevelation seeing something he cannot comprehend]]". And there's a sinister housekeeper, and Josiah's niece who isn't entirely uncreepy herself. Ace decides to crossdress for the occasion (mainly because her modern clothes causes people to call her a shameless trollop).

Still with us? As the story unfolds at a breakneck pace, it's soon revealed that the disturbingly creepy house might be haunted. Only it's not. It's the base for an alien surveillance force full of animated alien insectoid husks, the leader of which (Josiah himself) wishes to integrate themselves with the human race. In his opinion, that's best done by having Fenn-Cooper assassinate Queen Victoria and taking over England as its new King, as that's how evolution works in his mind.

The Doctor and Ace soon stumble across the fact that Josiah is ''not'' the leader of the expedition -- that's another being, who's being held prisoner within his own ship, which is currently beneath the mansion. This being is, best put, an Angel (not a [[Recap/DoctorWhoS29E10Blink weeping]] [[Recap/DoctorWhoS31E4TheTimeOfAngels one]], thankfully) going by the name of "Light". Light is dismayed to find himself back on Earth, particularly at the fact that everything has changed. He was just done cataloguing the whole thing when evolution just had to go and render all his work invalid. Then the Doctor talks to exotic bugs for a bit and wakes up a policeman who was locked in a drawer in suspended animation. As other plot threads, which include a commentary on evolution itself, as well as a lovely side-discussion of Java, resolve themselves very rapidly, Light essentially suffers from a blue screen of death as he comes to the realization that change sucks. His answer to all this change? ''[[MurderIsTheBestSolution Utterly eliminate all life on Earth using actual primordial soup]].'' They all discuss this over a nice dinner party while Ace, caught up in yet another plot thread, teaches an alien named Control how to be a lady.

The story finally comes down to the Doctor and Light having a verbal sparring match -- the Doctor finally [[TalkingTheMonsterToDeath talking Light into ending his own life]] so that he will no longer change. The space ship beneath the mansion decides to recruit a new crew, and enlists Control, who was formerly locked within the ship with fellow prisoners Light, Fenn-Cooper and Nimrod. Ship and crew then depart for places unknown while the Doctor talks to Ace about any regrets she may have in her life.

As it turns out, Ace encountered this place in her youth (in the future, with respect to the story's Victorian setting) and the evil feeling left behind from Josiah and Light pushed Ace into burning down the mansion. This resulted in a trauma as well as some time spent with meddling guidance counsellors. Ace's only regret after all this? That she didn't blow it up instead.

------

If you didn't follow any of that, don't worry. The script was already considered too long for the traditional four part story and was then ''compressed to three parts.''

The original pitch was set in a sinister house from ''the Doctor's'' childhood, on Gallifrey, but showrunner John Nathan-Turner asked for that aspect of it to be changed, as he felt it gave away too much about the Doctor at once. Creator/MarcPlatt went on to actually write that story as the notoriously confusing ''Literature/DoctorWhoNewAdventures'' GrandFinale "Lungbarrow". Ghost Light ended up being the final production of the original series, as it was produced ''after'' "[[Recap/DoctorWhoS26E3TheCurseOfFenric The Curse of Fenric]]" and "[[Recap/DoctorWhoS26E4Survival Survival]]", despite airing before both of them. [[note]]The final scene shot was of Light turning Gwendoline and her mother to stone, in case you're curious.[[/note]]

The DVD release contained a 45-minute documentary, a 30-minute interview and commentary that slowly filled in the gaps in what was missing and not entirely clear.

!!Tropes
* AllThereInTheManual: And how!
* ArchivePanic: Invoked in-canon. Light gets a severe case of this when he tries to catalogue all of Earth's life forms.
* ArsonMurderAndJaywalking:
--> '''The Doctor:''' "Let me guess: my heresies appall you, my theories outrage you, I never answer letters, and you don't like my tie."
** Then there's this exchange during dinner.
-->'''Josiah:''' I can provide a new order. Wealth! Prosperity!
-->'''Doctor:''' Confusion, wastage, tyranny, ''burnt toast!''
* YouFailBiologyForever: Josiah and his laughably inept grasp of evolutionary theory, though this trope could just as easily be the arc word for the serial as a whole, seeing how it skewers both Light's attempts to catalogue a neverending list of lifeforms and Victorian England's attitudes towards evolutionary science juxtaposed with their own rigid social hierarchy.
* {{Bifauxnen}}: Ace in Victorian men's clothes.
* BrainwashedAndCrazy: Gwendoline kills several people while under the influence of Josiah's mind control. The Doctor notes, however, that although Josiah was responsible for her actions, he wasn't responsible for how much enjoyment she got from carrying them out.
* BrandishmentBluff: The Doctor holds Josiah hostage with his radiation detector, which looks just enough like a gun to do the job.
* {{Camp}}: Light, the angelic SealedEvilInACan
* CatFight: Ace and Gwendoline. Twice.
* ContinuityNod:
** The Doctor asks if a gun is a [[Recap/DoctorWhoS14E6TheTalonsOfWengChiang Chinese fowling piece]].
** When Ace is discussing Perivale village with Mrs Grose, there is a nod to a scene in "[[Recap/DoctorWhoS24E4Dragonfire Dragonfire]]" where the Doctor reminisced about an earlier visit to Perivale.
* CreepyHousekeeper: Oh yes, and does she have a secret.
* DontWakeTheSleeper: Nimrod refers to Light as the "Sleeping One" who must not be woken.
* AFormYouAreComfortableWith: Light is not really an angel, or even humanoid; that's just the form he's "naturalised into".
* GoMadFromTheRevelation: Redvers Fenn-Cooper.
* GorgeousPeriodDress: Like "[[Recap/DoctorWhoS19E5BlackOrchid Black Orchid]]" before it, "Ghost Light" is a fine exemplar of a subclass of ''Who'' stories: the let's-raid-the-BBC-wardrobe-department serial.
* HamToHamCombat: Just name someone who ''isn't'' chewing the scenery in this episode. Now realize that all of the scenery-chewing just plain makes the adventure even more awesome.
* HauntedHouse: Played with. Even after the creepy occurrences in Gabriel Chase have been explained (well, sort of) by the story, in the events still leave a sense of evil and creepiness about the place which inspires Ace to burn it down in the future.
* KindlyHousekeeper: The daytime housekeeper fits this trope to a T, hitting all the checkmarks on it. She won't stay past 6pm though, because no one in their right mind would be there then. Which should tell you almost to the second when the TARDIS arrives.
* LetThePastBurn: Ace tried to invoke this by burning down Gabriel Chase. She wasn't counting on the Doctor bringing her back in time to before she did it.
-->'''Ace:''' When you're a kid you smash things you hate. But what do I do if it keeps coming back?
* LightIsNotGood
* MindScrew: "Ghost Light" has gained a reputation as one of the most incomprehensible ''Doctor Who'' episodes ever. Even being level with some episodes written by Steven Moffat.
* NamesToRunAwayFromReallyFast: subverted in the case of Nimrod the Neanderthal butler, who is probably the nicest character in the serial.
* NiceJobBreakingItHero: The Doctor frees Light believing that he can stop Josiah... not realising that he's trading from a fairly pathetic guy who wants to take over the British Empire to a full-blown OmnicidalManiac.
* NobleSavage: The Doctor claims Ace is this to excuse her scandalous clothing.
* OurAngelsAreDifferent: Light.
* POVCam: Used to show the Reverend Matthews' ... departure.
* PromotedFanboy: Writer Marc Platt was one of only two writers in the entire history of the series (the other being "[[Recap/DoctorWhoS18E3FullCircle Full Circle]]" writer Andrew Smith) to have a script accepted with no professional writing experience whatsoever, and no writing background beyond ''Doctor Who'' fanfiction. And [[TropesAreNotBad the result]] is one of the Seventh Doctor's most high-concept and original adventures.
* RightOnTheTick: The house's inhabitants come to life when the clock in the hall strikes six. (The Doctor lampshades the fact that it's not WhenTheClockStrikesTwelve.) When the Doctor's plans come to fruition a little early, he puts the clock on by a quarter of an hour so they're all there to see it happen.
* ScrewTheMoneyIHaveRules: Josiah tries to get the Doctor on his side by offering a bribe of 5000. He fails.
* ShoutOut:
** Q: "Who was it who said Earth men never invite their ancestors round for dinner?" A: Creator/DouglasAdams, author of ''Franchise/TheHitchhikersGuideToTheGalaxy'', former script editor for ''Series/DoctorWho'' and author of such episodes as "[[Recap/DoctorWhoS16E2ThePiratePlanet The Pirate Planet]]", "[[Recap/DoctorWhoS17E2CityOfDeath City of Death]]", and the sadly unfinished "[[Recap/DoctorWhoS17E6Shada Shada]]".
** Mrs Grose, the day housekeeper, is a reference to the character of the same name in ''Literature/TheTurnOfTheScrew''.
** Inspector Mackenzie shares his name with the antagonist of the ''Literature/{{Raffles}}'' stories.
** The subplot with Control's desire to be "a ladylike" contains many shout-outs to ''{{Theatre/Pygmalion}}''.
** Redvers Fenn-Cooper's surname may be an allusion to Creator/JamesFenimoreCooper.
** Ace compares Josiah's aversion to sunlight to Dracula, and tries the old pull-back-the-curtain trick on him (unfortunately just after he'd levelled up and lost that weakness).
** When the Doctor is messing with Light by listing mythical creatures that Light "missed" when he catalogued Earth's lifeforms, he throws in a couple of the creatures from Creator/LewisCarroll's poem "Literature/{{Jabberwocky}}".
* SoWasX: Or in this case, So Am I.
--> '''Josiah:''' I'm as human as you are. \\
'''Doctor:''' ''[[HumanAliens Yes.]]''
* SufficientlyAdvancedAliens: The Doctor, obviously, but also Light, Smith, Control and Nimrod.
* SummonBiggerFish: The Doctor's plan to deal with Josiah, with quite disastrous results.
* TakenForGranite: Gwendoline and her mother. In what turned out to be the last scene ever filmed for the original series, bringing an extra dimension to the words "Well... you'll never change again."
* TalkingTheMonsterToDeath: Light is infuriated by the fact that the Earth has changed, making the inventory he was working on meaningless. He resolves to destroy the Earth so it will stop changing. The Doctor points out the idiocy of thinking that you can stop change, and that everything in the universe is changing, ''including Light''. Light commits suicide because he considers change a FateWorseThanDeath.
* TaxidermyTerror: Ace gets trapped in a room full of this, and freaks out.
* TemptingFate:
** "While we have the lamp, we're safe!"
** "Nonsense, young lady. That thing isn't dangerous."
* ThirdPersonPerson: "Poor Redvers...[[GoMadFromTheRevelation his hair turned white]]."
* ViewersAreGeniuses: Any scenes where the plot stopped for people to explain what was going on were excised in the editing stage because there genuinely wasn't enough running time in which to fit any of them in, resulting in great swathes of plot that are never actually explicitly explained within the story at all and thus have to be put together by the audience themselves. Considering how complicated the plot is in the first place, this task proves easier said than done.
* WhatTheHellHero: Ace was horribly traumatised by the creepy atmosphere of the mansion in her own time, so the Doctor decides to take her back to find out what happened ''without informing her beforehand''. She is obviously somewhat upset about this.