[[quoteright:350:http://static.tvtropes.org/pmwiki/pub/images/spiderback_5089.jpg]]
[[caption-width-right:350:"[[Recap/DoctorWhoS30E2TheFiresOfPompeii Daughter of London...]] [[Recap/DoctorWhoS30E11TurnLeft there is something on your back.]]"]]

->''"Is that fear I can feel in your mind? You are not accustomed to feeling frightened, are you Doctor? You are very wise to be afraid of '''me'''!"''
-->-- '''The Great One'''

Sarah Jane visits her friend Mike Yates at a crypto-Buddhist retreat in the English countryside. Some of them have apparently been skipping meditation lessons to hang out in the basement and summon ENORMOUS FREAKING SPIDERS from Metebelis III, a world ruled by the terrifying things. As if enormous spiders weren't bad enough, these are ''enormous telepathic '''mind-controlling''' spiders'', and one of them takes over a Buddhist and turns him into a spider-puppet. Naturally, they have designs on our world; but their chief aim at the moment is the recapture of a blue crystal prism thingy. Conveniently enough, the Doctor has just received one in the mail! It's from Jo Grant, who he gave it to back in "[[Recap/DoctorWhoS10E5TheGreenDeath The Green Death]]".

Puppet guy follows Sarah Jane back to UNIT HQ to steal the Metebelis crystal, using mind-thrown lightning bolts to get past security. Awesome. Psychic powers so rarely come with offensive capabilities. A completely badass [[Main/FlyingCar hovercar]] vs. helicopter chase ensues, but the guy gets away. The Doctor and Sarah Jane deduce who the thief must have been, and head back to the retreat--but by then the puppet guy has misplaced it.

The evil monks turn a mandala into a portal to Metebelis III, and puppet guy goes through. Sarah Jane, who really should know better than to step into glowing circles on the ground, finds herself there as well. She tries to foment glorious revolution amongst the human proletariat, but their arachnid overlords promptly arrive to put an end to ''that''. She is saved by the timely intervention of the Doctor--who's used the TARDIS and the crystal to get to Metebelis III himself--the spiders attack him, leave him for dead, and go back for reinforcements. They're back bright and early the next morning to haul Doctor and Companion back to Spider HQ, where they have obviated prison cells by the simple expedient of swaddling their prisoners in spider silk.

The Doctor wiggles out of his cocoon, frees Sarah Jane, and decides to put the crystal back into the cave where it was found in the first place, on the theory that it will placate the intelligence that spawned it. But the radiation will surely kill anyone who enters the cave! If only there were some brave hero willing to sacrifice his life to replace the crystal! One who could, if he ''were'' to die, regenerate into Creator/TomBaker!

[[ForegoneConclusion If]] [[Recap/DoctorWhoS12E1Robot only...]]

!!Tropes

* [[{{NamesToRunAwayFrom/TheAdjectiveOne}} The Adjective One]]: The Great One.
* AlienAmongUs: K'Anpo is actually another renegade Time Lord.
* AllWebbedUp: The spiders' captives are nicely webbed up in preparation for dinner.
* AuthorAppeal: The Buddhist themes were written into the episode by Barry Letts, himself a practicing Buddhist. This came back to bite him slightly, as some Buddhists objected to the use of mantras and chants as a means to summon the spiders.
* BackForTheFinale: Mike returns to redeem himself after getting booted out of UNIT for his betrayal in Invasion of the Dinosaurs.
* BadassNormal: Sgt. Benton. The mind-thrown lightning bolts instantly kill normal humans, and seriously inconvenience the Doctor. Benton takes two to the chest, and shakes it off with enough wherewithal to bring the car around.
** He also makes a damn fine cup of coffee.
* BigCreepyCrawlies: The Eight-Legs, especially their leader.
* BookEnds: Jon Pertwee's run as The Doctor begins and ends with him stumbling out of the TARDIS and collapsing.
* {{Catchphrase}}
-->"ALL PRAISE TO THE GREAT ONE!"
* CallBack:
** The Metebelis crystal from ''[[Recap/DoctorWhoS10E5TheGreenDeath The Green Death]]'' makes a return, complete with a letter from Jo Grant.
** Although it isn't explicitly stated, it's widely assumed that K'Anpo is the hermit the Doctor remembered in the "daisiest daisy" monologue in ''[[Recap/DoctorWhoS9E5TheTimeMonster The Time Monster]]''.
* ChekhovsGun: While it's quite clear from the start that the Metebelis crystal is the MacGuffin of this story, we didn't know so [[Recap/DoctorWhoS10E5TheGreenDeath back when it first appeared.]]
* ComboPlatterPowers: When the spiders possess people, they give them PsychicPowers and the ability to [[ShockAndAwe shoot bolts of lightning from their hands]]. [[RetroactiveRecognition Three years later]], these seemingly unrelated abilities [[StarWars would come together again]]...
* ContemplateOurNavels: A rather literal example. When Mike Yates first brings Sarah Jane in and they look in on some of the actual meditation.
-->'''Mike:''' They're just meditating. Watching.
-->'''Sarah Jane:''' So what are they watching?
-->'''Mike:'''They're mentally watching their tummies. Go up and down as they breathe.
-->'''Sarah Jane:''' Like contemplating their bellybuttons?
-->'''Mike:''' You could put it like that.
-->'''Sarah Jane:''' Well, I hope you all know what you're on about.
-->'''Mike:''' Probably seems a bit daft. It's an exercise in awareness really.
* DeceptiveDisciple: Lupton to K'Anpo
* [[DistractedByTheShiny Distracted By The Pretty]]: Tommy.
* DoubleTake: Sarah Jane gives a quite incoherent explanation of her discovery of the spider summoning ritual, and the Doctor doesn't really listen. That is, until he realises she's talking about spiders.
* DrivingADesk: While most parts of the chase scene look good, the Whomobile part looks... off.
* FamousLastWords: "A tear, Sarah Jane? No, don't cry. While there's life, there's..."
* FlowersForAlgernonSyndrome: Tommy. Unusually for this trope, there's no sign that Tommy loses his newfound intelligence at the end.
* FlyingCar: The Whomobile.
* FromNobodyToNightmare: Lupton was a former salesman and manager for 25 years who was embittered when his company fired him.
* GiantSpider: Lots 'n lots.
* AGodAmI: the Great One's desire
* GodSaveUsFromTheQueen
* GoneHorriblyRight: The Great One's plan.
* GrandFinale: To the Pertwee era as a whole as it features a callback to Jo, Yates' return and acts as a loose sequel to Invasion of the Dinosaurs and The Green Death.
* HereWeGoAgain: Said verbatim by the Brigadier when the Doctor regenerates.
* IKnowYouAreInThereSomewhereFight: The Doctor, to spider-controlled Sarah Jane
* ILoveNuclearPower
* IncorruptiblePurePureness: Protects Tommy from the spider-people's lightning bolts.
* InspirationallyDisadvantaged: Tommy
* KneelBeforeZod: the Great One tormenting the Doctor in part 5
* LaResistance
* LargeHam: The Great One toward the end.
* LeftForDead
* LoadBearingBoss: Crossed with MadeOfExplodium. When The Great One dies, her underground lair explodes, which brings down half the mountain it's beneath.
* LostColony: the human colony on Metebelis III.
* MagiciansAreWizards: Clegg
* MineralMacGuffin
* MoreExpendableThanYou: Benton tries this in Part 2. The Doctor shoots him down immediately.
* TheNthDoctor: [[LampshadeHanging Somewhat lampshaded]] when the Brig [[CallBack recalls]] that [[Recap/DoctorWhoS7E1SpearheadFromSpace the Second Doctor became the Third Doctor]]. K'Anpo also regenerates at the end of the story.
* NamesToRunAwayFromReallyFast: Huath, the Queen spider, is Old Irish for "fear".
* NegateYourOwnSacrifice: The Doctor.
* NotListeningToMeAreYou: The Doctor is more interested in the Metebelis crystal than in Sarah Jane's story about a summoning ritual in the monastry. She calls him out on it, not that it helps. Until she mentions a big spider...
* NotSoPhonyPsychic: Professor Clegg is a real psychic who disguises his talent as a magic trick.
* OOCIsSeriousBusiness: As lampshaded by the Great One re the Doctor.
* OminousLatinChanting: Ominous Buddhist chanting ("Oṃ maṇi padme hūṃ!") is used to summon the giant spiders.
* OneGenderRace: The spiders, apparently.
* PhlebotinumOverdose
* PokeInTheThirdEye: Clegg's death, apparently due to using the crystal while the spider is coming across.
* PowerCrystal
* PsychicPowers
* PuppeteerParasite: with some remaining free will. Lupton in particular finds himself able to telepathically torture his spider right back when she tries doing it to him.
* ReligionIsMagic
* TheShangriLa
* ShockAndAwe: The spiders have this power, and so have the humans possessed by them.
* SpidersAreScary
* TheStarscream: Lupton's spider to the Queen.
* TwoAliasesOneCharacter: Cho-je and K'anpo Rinpoche are the same entity, with Cho-je serving as a sort of future projection of K'anpo that merges with him for his regeneration. Since Sarah Jane is unfamiliar with regeneration, she understandably gets the two confused at the end:
-->'''Sarah Jane Smith:''' This is the abbot of-- no, it's Cho-je. I mean, it looks like Cho-je -- but it's really K'anpo Rinpoche ... I think.
-->'''Brigadier Lethbridge-Stewart:''' Thank you. [[DeadpanSnarker That makes everything quite clear.]]
* WagTheDirector: By Proxy: The massive (and completely gratuitous) car chase that takes up most of the second episode was the writers' farewell gift to Jon Pertwee, who appreciated any excuse to drive motor vehicles very fast.
* WeWillUseManualLaborInTheFuture
* WelcomeBackTraitor: Although Yates doesn't rejoin [=UNIT=], Sarah and the Doctor are very trusting of him despite [[Recap/DoctorWhoS11E2InvasionOfTheDinosaurs that nasty "Golden Age" business]].
* WhatTheHellHero: K'Anpo does this, controversially, but the Doctor did provoke the whole mess by stealing the crystal, and his reaction to getting Professor Clegg killed is pretty cold.
* TheXOfY
* YouLookFamiliar:
** Professor Clegg is the third nervous scientist played in the series by Cyril Shaps, after [[Recap/DoctorWhoS5E1TheTombOfTheCybermen Viner]] and [[Recap/DoctorWhoS7E3TheAmbassadorsOfDeath Lennox]].
** And a case of You Sound Familiar: Lupton was previously the voice of [[Recap/DoctorWhoS10E5TheGreenDeath the BOSS]].

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''All praise to the Great One!''
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