[[caption-width-right:350:She's still alive.]]

''[[http://www.fimfiction.net/story/109545/a-trusted-friend-in-science-and-ponies A Trusted Friend in Science and Ponies]]'' is a FanSequel to ''FanFic/BetterLivingThroughScienceAndPonies'' written by Tropers/{{Rethkir}}. Like its predecessor, it is a {{crossover}} fic between ''WesternAnimation/MyLittlePonyFriendshipIsMagic'' and ''VideoGame/{{Portal}}''.

It is an ongoing fic, first written two years after the publication of the original in response to its SequelHook and lack of a sequel. The story takes place following the events of the original, continuing the StoryArc. Picking up where the original left off, it is a longer and more in-depth tale that chronicles [=GLaDOS=]'s plan to rebuild Aperture Science and the emotional turmoil it causes for Chell and her friends in Ponyville.

Spoilers for ''FanFic/BetterLivingThroughScienceAndPonies'' will be unmarked.

After saving Equestria from [=GLaDOS=]'s evil, Chell is finally able to live the life she never had... until [=GLaDOS=] sets in motion her plan to rebuild Aperture Science. It's only a matter of time before the experiments begin again, and only Chell will be able to stop her.

!! Tropes that appear in this story:
* AddedAlliterativeAppeal: The title of Chapter 3 is "The Practical Purpose of Portals."
* AntiMagic: Again, the magic-restricting cones.
** Emancipation grills are shown to also block the use of magic through them.
* ArcWords: The phrase "still alive" is said a lot early on.
* AscendedFanon: As of chapter 20, ''VideoGame/PortalPrelude'' is considered canon to this story.
* TheAtoner: [[spoiler:Wheatley]]
* BadDreams: [=GLaDOS=] of all characters has one in chapter 10.
** Chell has her own in chapter 13.
* [[spoiler:BroughtDownToNormal: Princess Celestia.]]
* [[spoiler:[[LukeIAmYourFather Chell, I Am Your Mother]]]]
* ComedicSociopathy: The way [=GLaDOS=] disregards the Diamond Dogs can be quite humorous.
* ComplexityAddiction: [=GLaDOS=]' plan is a lot more complicated than it probably needs to be.
* ContinuityNod: It's filled to the brim with them, both for ''VideoGame/{{Portal}}'' and, and for ''FanFic/BetterLivingThroughScienceAndPonies''.
** Ditzy calls [=GLaDOS=] a monkey wrench in chapter 9.
** Many of [=GLaDOS=] lines are references to things she said in ''VideoGame/{{Portal}}'' or '' VideoGame/{{Portal 2}}''.
** When [=GLaDOS=] first speaks to Chell, she mentions that it felt like she was ignoring her in the ''VideoGame/{{Portal}}'' games, which is, according to WordOfGod, the real reason why she [[HeroicMime never talked]].
** When [=GLaDOS=] escapes from the facility, she is described as flying like an eagleÖ piloting a blimp.
** When she first contacts Rarity, she describes herself as having a medical degreeÖ in fashionÖ from [[foldercontrol]]

[[folder: insert [[Fantasy Counterpart Culture French counterpart nation ]]
** [=GLaDOS=] repeats many of the insults she used on the Mane 6 before.
** [=GLaDOS=] sings a new version of Still Alive in the first chapter.
* CoolAndUnusualPunishment: [=GLaDOS=] punishes Rover by [[spoiler:forcing him to listen to a repeating audio recording of Rarity whining for the rest of his life.]] Her punishment of the other two Diamond Dogs is genuinely terrifying, although Rover considers his punishment to be worse.
* CurbStompBattle: [[spoiler:[=GLaDOS=] doesn't even try to win the fight against Chell and her friends in chapter 20.]]
* {{Crossover}}: With ''VideoGame/{{Portal}}'', ''WesternAnimation/MyLittlePonyFriendshipIsMagic'', and [[spoiler:''VideoGame/HalfLife''.]]
* DarkerAndEdgier: Very much so compared to the prequel. The tone of this sequel is far darker and heavyhearted than the original.
* DepartmentOfRedundancyDepartment: Some of [=GLaDOS=]' dialog is this way for humor.
* TheDeterminator: No points for guessing that Chell fits this bill, but she takes it to the extreme in chapter 20 [[spoiler:during her fight with [=GLaDOS=], when she refuses to give up even after she's been defeated.]]
* DramaticIrony: Used in the beginning when the ponies are unaware that [=GLaDOS=] is still alive.
* EnemyEatsYourLunch: [=GLaDOS=] steals a cake that Pinkie Pie made [[spoiler:and eats it]].
* EvilCounterpart: [=GLaDOS=] is this to Celestia, since they look very similar and love cake. They are also {{foil}}s to each other.
* FanSequel
* FireWaterJuxtaposition: [[spoiler:Fluttershy's sacrifice takes place in a forest fire, as it begins to rain.]]
* {{Foil}}: Celestia and [=GLaDOS=] are foils to each other, as they share a similar appearance and both love cake, but have very different personalities.
* ForcedToWatch: [=GLaDOS=]'s plans to to make Chell watch [[spoiler:the destruction of Equestria and her friends.]]
* {{Foreshadow}}: There's a healthy amount throughout, but Chapter 6 takes the cake, no pun intended.
* FreudianExcuse: This fic delves into the reason why [=GLaDOS=] changed after ''VideoGame/{{Portal2}}'', and generally attempts to cast [=GLaDOS=] in a sympathetic light, despite the terrible things she does throughout the story.
* FrickinLaserBeams: [=GLaDOS=]'s laser canon becomes her signature weapon.
* GhostMemory: [=GLaDOS=] obtains Caroline's memories early on. [[spoiler:You'd better believe it's a ChekhovsGun.]]
* GreaterScopeVillain: [[spoiler:The Combine]] is this throughout the first half of the story, as [=GLaDOS=] drives the plot by attempting to [[spoiler:bring them to Equestria.]]
* HeroicBSOD: Happens to Chell when she finds out that [=GLaDOS=] is still alive. Ditzy is able to pull her out of it.
* HeroicSacrifice: [[spoiler:Fluttershy sacrifices herself to save some animals.]] (She doesn't quite die, though.)
* KillTheCutie: Almost happens to [[spoiler:Fluttershy]]. The readers were not taking it well.
* LateArrivalSpoiler: It's very hard to talk about this story without spoiling the ending of the original, considering that [=GLaDOS=] being NotQuiteDead was a TwistEnding.
* LeaningOnTheFourthWall: [=GLaDOS=] offers this gem: "Donít give me one of your stupid pretentious ''friendship'' lessons. Iíd watch a show for little girls if I wanted to hear that. I swear, I feel like Iím in one when Iím around you stupid, happy ponies."
** And of course, there's Pinkie: "Oh, Rarity, you donít need to address me with expositional dialog explaining the characters, setting, and situation. Thatís what the narrationís for."
* LogicBomb: Pinkie Pie attempts one on [=GLaDOS=] involving OppositeDay. [[spoiler:It doesn't work.]]
* MechanicalHorse: [=GLaDOS=] has adjusted very well to her new body.
* MundaneUtility: Celestia and Chell agree the portal guns could easily fall into the wrong hands, and so limit their usage to creating an Equestria-wide transit system via the portals, keeping the guns locked up after.
* NearDeathExperience: [[spoiler:Fluttershy has one in chapter 8.]]
* PeoplePuppets: [[spoiler:How [=GLaDOS=] brings Atlas and P-Body back.]]
** She does this later with [[spoiler:Princess Celestia, except this time, [=GLaDOS=] is the puppeteer.]]
* PillarOfLight: The [[spoiler:Anti-Mass Spectrometer]] produces a spectacular one whenever it is used.
* PortalCut: Chell explains why this doesn't happen in chapter 3.
* PortalNetwork: Utilized for transportation in Equestria during the TimeSkip.
* [[PoweredByAForsakenChild Powered By A Forsaken Pony]]: Poor Twilight.
* PrecisionFStrike: In chapter 20, courtesy of Chell.
* {{Pyromaniac}}: [=GLaDOS=] loves burning things with that laser.
* RecursiveFanfiction
* SequelEscalation: Itís significantly longer than the original and has a more intricate plot, and all of Equestria is now at stake.
* ShoutOut:
** The [[spoiler:anti-mass spectrometer]] requires [[Film/BackToTheFuture 1.21 gigawatts]] of power.
** Chell and Ditzy briefly meet [[Series/DoctorWho the Doctor]]. He calls Ditzy "Derpy" and mentions that they've been on adventures before, a reference to AudioPlay/DoctorWhoovesAndAssistant. He asks if there are any [[ZeppelinsFromAnotherWorld Zeppelins]] and mentions knocking four times.
** The pegasi that Rainbow Dash selects to assist Fluttershy with the animal rescue are some of the main characters in ''FanFic/AceCombatTheEquestrianWar''.
** Pinkie speculates using Chell's necklace to allow dogs to talk, a reference to ''WesternAnimation/{{Up}}''.
** [=GLaDOS=] attempts to activate Twilight's powerful magical state by saying [[WesternAnimation/AvatarTheLastAirbender "yip-yip."]]
*** Later, Celestia quotes Uncle Iroh.
** [=GLaDOS=] places a [[VideoGame/TheLegendOfZeldaMajorasMask Moon's Tear]] in the [[spoiler:anti-mass spectrometer.]]
** The Space Core sings [[WesternAnimation/{{Futurama}} "Whalers on the Moon"]] and the Franchise/StarWars theme.
** In chapter 20, [=GLaDOS=] plays the FinalBoss theme of ''VideoGame/PortalPrelude'' and references the game.
* SkewedPriorities: [=GLaDOS=] is relieved that the giant snake eating Spot is not venomous because [[spoiler:she could only say IWarnedYou for giant snakes, not giant ''venomous'' snakes.]] Her priorities in general are pretty skewed.
* TheMindIsAPlaythingOfTheBody: [[spoiler:[=GLaDOS=] was corrupted again when after she came back in her old body at the end of ''VideoGame/{{Portal 2}}''.]]
* TimeSkip: A few months pass during chapter 3.
* TrailersAlwaysLie: [[spoiler:Chell in fact does not stop [=GLaDOS=], and in fact is instrumental in her evil plan succeeding.]]
* {{Tsundere}}: [=GLaDOS=], big time. It becomes apparent during chapter 10, as her personality becomes more erratic and switches between mean and kind.
* YouCantThwartStageOne: [[spoiler:Nopony is able to stop [=GLaDOS=] from bringing the Combine to Equestria.]]
* YouHaveFailedMe: [=GLaDOS=] is not very forgiving to her Diamond Dog minions.