History SequelEpisode / LiveActionTV

* ''Series/DoctorWho'':
** [[Recap/DoctorWhoS3E2MissionToTheUnknown "Mission to the Unknown"]], the Dalek Cutaway, led into [[Recap/DoctorWhoS3E4TheDaleksMasterPlan "The Daleks' Master Plan"]], two serials later. The latter story also follows up [[Recap/DoctorWhoS2E9TheTimeMeddler "The Time Meddler"]] with the return of the Monk.
** "[[Recap/DoctorWhoS4E6TheMoonbase The Moonbase]]" is sequel to "[[Recap/DoctorWhoS4E2TheTenthPlanet The Tenth Planet]]" in that it's the second appearance of the Cybermen in practically the same plot. A deleted line mentioned the Cybermen's Tombs on Telos, which leads into their next appearance, "[[Recap/DoctorWhoS5E1TheTombOfTheCybermen The Tomb of the Cybermen]]".
** [[Recap/DoctorWhoS5E2TheAbominableSnowmen "The Abominable Snowmen"]] set up a long chain of sequel stories that would establish important elements of the Whoniverse. First there was [[Recap/DoctorWhoS5E5TheWebOfFear "The Web of Fear"]], which brought back the Great Intelligence and Professor Travers. Then there was [[Recap/DoctorWhoS6E3TheInvasion "The Invasion"]], which saw Colonel Lethbridge-Stewart promoted to Brigadier and UNIT established, plus a SuspiciouslySimilarSubstitute for Professor Travers and his daughter Ann. Then came [[Recap/DoctorWhoS7E1SpearheadFromSpace "Spearhead from Space"]], which followed up on what happened to the Brigadier and UNIT since "The Invasion" and reunited him with the Doctor, who he initially doesn't recognize on account of his regeneration. Finally, [[Recap/DoctorWhoS8E1TerrorOfTheAutons "Terror of the Autons"]] featured the Master (in his debut appearance) stealing a meteorite that was left behind after the events of "Spearhead from Space" in order to reawaken the Autons and summon the Nestene Consciousness back to Earth, which set off a whole season full of successive clashes between the Doctor and the Master.
** [[Recap/DoctorWhoS9E2TheCurseOfPeladon "The Curse of Peladon"]] was followed up by [[Recap/DoctorWhoS11E4TheMonsterOfPeladon "The Monster of Peladon"]], depicting the next generation of Peladon's monarchy attempting to wrestle another flareup in xenophobia and nationalism after the kingdom joined the Galactic Federation. The serial even reused the same sets.
** [[Recap/DoctorWhoS9E3TheSeaDevils "The Sea Devils"]] is a sequel to [[Recap/DoctorWhoS7E2DoctorWhoAndTheSilurians "Doctor Who and the Silurians"]], in that it established the titular monsters as cousins. It additionally acts as a sequel to [[Recap/DoctorWhoS8E5TheDaemons "The Dæmons"]], following up on the Master's arrest at the end of that serial and seeing him engineer the Sea Devils' invasion of humankind while behind bars. [[Recap/DoctorWhoS21E1WarriorsOfTheDeep "Warriors of the Deep"]] was a sequel to both Silurian stories.
** [[Recap/DoctorWhoS10E4PlanetOfTheDaleks "Planet of the Daleks"]] is a sequel to both [[Recap/DoctorWhoS10E3FrontierInSpace "Frontier in Space"]], immediately following up on the {{cliffhanger}} ending of that story and the Daleks' plot to invade Earth and Draconia, and [[Recap/DoctorWhoS1E2TheDaleks "The Daleks"]], seeing the Doctor work with a new generation of Thals long after his initial visit to Skaro, by which point his exploits from that story have become the stuff of legend. Of note is that "Frontier in Space" and "Planet of the Daleks" were originally intended to be billed as one twelve-part serial (which would've tied it with [[Recap/DoctorWhoS3E4TheDaleksMasterPlan "The Daleks' Master Plan"]] for the position of longest story by episode count) before being DividedForPublication as two interconnected six-parters.
** All the Dalek stories from [[Recap/DoctorWhoS12E4GenesisOfTheDaleks "Genesis of the Daleks"]] until [[Recap/DoctorWhoS25E1RemembranceOfTheDaleks "Remembrance of the Daleks"]] follow an ongoing story involving the Doctor's conflict with Davros, which set both the Dalek Civil War and the Last Great Time War in motion.
** [[Recap/DoctorWhoS15E6TheInvasionOfTime "The Invasion of Time"]] follows up on [[Recap/DoctorWhoS14E3TheDeadlyAssassin "The Deadly Assassin"]], featuring the Doctor returning to Gallifrey again to claim the title of Lord President. In the earlier serial, he nominated himself for the position to weasel out of a sham trial, and the only other known candidate, Goth, was killed by the Master, making the Doctor the winner by default.
** Creator/PeterDavison's first year had a story called [[Recap/DoctorWhoS19E3Kinda "Kinda"]], in which a plot point was a snake-like being called the Mara gaining influence over Tegan to further its goals. The next year saw the story [[Recap/DoctorWhoS20E2Snakedance "Snakedance"]], penned by the same writer, in which we learn that the Mara still has control over Tegan and possesses her once again in order to achieve physical form. There were plans for a third outing, but nothing came of fit.
** [[Recap/DoctorWhoS20E1ArcOfInfinity "Arc of Infinity"]] is a sequel to [[Recap/DoctorWhoS10E1TheThreeDoctors "The Three Doctors"]], in that it saw the return of Omega.
** [[Recap/DoctorWhoS22E1AttackOfTheCybermen "Attack of the Cybermen"]] is a sequel to three separate serials. In chronological order, it follows up on [[Recap/DoctorWhoS4E2TheTenthPlanet "The Tenth Planet"]] by featuring the Cybermen attempting to go back in time to prevent the destruction of Mondas during that serial, [[Recap/DoctorWhoS5E1TheTombOfTheCybermen "The Tomb of the Cybermen"]] by being set in the titular tombs and elaborating upon how and why the Cybermen set up shop on Telos, and [[Recap/DoctorWhoS21E4ResurrectionOfTheDaleks "Resurrection of the Daleks"]] by bringing back the mercenary Lytton.
** [[Recap/DoctorWhoS22E5Timelash "Timelash"]] is a sequel to an ''[[NoodleIncident untelevised]]'' adventure the Third Doctor had with Jo.
** [[Recap/DoctorWhoS24E1TimeAndTheRani "Time and the Rani"]] to [[Recap/DoctorWhoS22E3TheMarkOfTheRani "The Mark of the Rani"]].
** [[Recap/DoctorWhoS27E11BoomTown "Boom Town"]] continues the story of a Slitheen who survived the events of [[Recap/DoctorWhoS27E4AliensOfLondon "Aliens of London"]]/[[Recap/DoctorWhoS27E5WorldWarThree "World War Three"]].
** [[Recap/DoctorWhoS27E2TheEndOfTheWorld "The End of the World"]], [[Recap/DoctorWhoS28E1NewEarth "New Earth"]] and [[Recap/DoctorWhoS29E3Gridlock "Gridlock"]] are season-apart stories loosely connected to the Face of Boe's final message to the Doctor.
** Satellite Five (and all the mess the Doctor's involvement caused) reappears in [[Recap/DoctorWhoS27E12BadWolf "Bad Wolf"]]/[[Recap/DoctorWhoS27E13ThePartingOfTheWays "The Parting of the Ways"]], after an assumed one-off encounter with the Mighty Jagrafess in [[Recap/DoctorWhoS27E7TheLongGame "The Long Game"]].
** While ''Series/{{Torchwood}}'' was a recurring {{Arc Word|s}} in series 2 (with the Doctor meeting a group identifying as the Torchwood Archive in [[Recap/DoctorWhoS28E8TheImpossiblePlanet "The Impossible Planet"]]/[[Recap/DoctorWhoS28E9TheSatanPit "The Satan Pit"]]), the Doctor's only direct encounters were at the founding in [[Recap/DoctorWhoS28E2ToothAndClaw "Tooth and Claw"]] and his capture by ([[spoiler:and the subsequent slaughtering of the team of by the real villains]]) Torchwood London in [[Recap/DoctorWhoS28E12ArmyOfGhosts "Army of Ghosts"]]/[[Recap/DoctorWhoS28E13Doomsday "Doomsday"]].
** The Dalek episodes from "Army of Ghosts"/"Doomsday" to [[Recap/DoctorWhoS30E13JourneysEnd "Journey's End"]] directly follow on from one another. [[spoiler:Depending on interpretation, the surviving Daleks from [[Recap/DoctorWhoS31E3VictoryOfTheDaleks "Victory of the Daleks"]] may have come from the Dalek invasion of [[Recap/DoctorWhoS30E12TheStolenEarth "The Stolen Earth"]].]] A similar use happens with Cybus Cyberman stories from [[Recap/DoctorWhoS28E5RiseOfTheCybermen "Rise of the Cybermen"]] to [[Recap/DoctorWhoS30E14TheNextDoctor "The Next Doctor"]], which, subsequently, also involves the aforementioned "Army of Ghosts".
** [[Recap/DoctorWhoS30E17E18TheEndOfTime "The End of Time"]] picks up from [[spoiler:the Master's death]] at the end of [[Recap/DoctorWhoS29E13LastOfTheTimeLords "Last of the Time Lords"]].
** Series 4, 5 and 6 have a recurring string of non-consecutive River Song episodes ([[Recap/DoctorWhoS30E8SilenceInTheLibrary "Silence in the Library"]]/[[Recap/DoctorWhoS30E9ForestOfTheDead "Forest of the Dead"]]; [[Recap/DoctorWhoS31E4TheTimeOfAngels "The Time of Angels"]]/[[Recap/DoctorWhoS31E5FleshAndStone "Flesh and Stone"]], [[Recap/DoctorWhoS31E12ThePandoricaOpens "The Pandorica Opens"]]/[[Recap/DoctorWhoS31E13TheBigBang "The Big Bang"]]…) though from her point of view, they're prequel episodes.
** Series 5's [[Recap/DoctorWhoS31E11TheLodger "The Lodger"]], a BreatherEpisode just before the series 5 finale, was followed by series 6's [[Recap/DoctorWhoS32E12ClosingTime "Closing Time"]], a BreatherEpisode just before the series 6 finale.
** The 50th anniversary special [[Recap/DoctorWho50thASTheDayOfTheDoctor "The Day of the Doctor"]] has two sequel multi-part episodes in Series 9 (which aired two years later):
*** [[Recap/DoctorWhoS35E7TheZygonInvasion "The Zygon Invasion"]]/[[Recap/DoctorWhoS35E8TheZygonInversion "The Zygon Inversion"]] is a sequel to the B-plot, revealing what happened to the Zygons after the Doctor foiled their scheme.
*** The finale three-parter [[Recap/DoctorWhoS35E10FaceTheRaven "Face the Raven"]]/[[Recap/DoctorWhoS35E11HeavenSent "Heaven Sent"]]/[[Recap/DoctorWhoS35E12HellBent "Hell Bent"]] is a sequel to the A-plot as [[spoiler:the Doctor returns to Gallifrey at last]]. "Face the Raven" itself doubles as a sequel to both Series 8's [[Recap/DoctorWhoS34E9Flatline "Flatline"]], as Rigsy needs Clara and the Doctor's help once more, and [[Recap/DoctorWhoS35E5TheGirlWhoDied "The Girl Who Died"]]/[[Recap/DoctorWhoS35E6TheWomanWhoLived "The Woman Who Lived"]] from earlier in this season, as [[spoiler: Ashildr/Me returns]].

{{Sequel Episode}}s in live-action TV.

** The {{Halloween Episode}}s for the final two seasons: "[[Recap/FamilyMattersS8E5Stevil Stevil]]" and "[[Recap/FamilyMattersS9E7StevilIIThisTimeHesNotAlone Stevil II: This Time, He's Not Alone]]". They detail [[DemonicDummy Steve's titular ventriloquist dummy coming to life]] and seeking to off not only his owner, but the entire household, as well, with the latter episode (hence the title) featuring an evil dummy modeled after Carl, named Carlsbad.

** The {{Halloween Episode}}s for the final two seasons: "[[Recap/FamilyMattersS8E5Stevil Stevil]]" and "Stevil II: This Time, He's Not Alone". They detail [[DemonicDummy Steve's titular ventriloquist dummy coming to life]] and seeking to off not only his owner, but the entire household, as well, with the latter episode (hence the title) featuring an evil dummy modeled after Carl, named Carlsbad.

** The {{Halloween Episode}}s for the final two seasons: "Stevil" and "Stevil II: This Time, He's Not Alone". They detail Steve's titular ventriloquist dummy coming to life and seeking to off not only his owner, but the entire household, as well, with the latter episode (hence the title) featuring an evil dummy modeled after Carl, named Carlsbad.

** The {{Halloween Episode}}s for the final two seasons: "Stevil" and "Stevil II: This Time, He's Not Alone". They detail Steve's titular ventriloquist dummy coming to life and seeking to off not only his owner, but the entire household, as well, with the latter episode featuring an evil dummy modeled after Carl, named Carlsbad.

** The {{Halloween Episode}}s for the final two seasons: "Stevil" and "Stevil II: This Time, He's Not Alone". They detail Steve's titular ventriloquist dummy coming to life, with the latter episode featuring one modeled after Carl, named Carlsbad.

* In ''Series/TheFlash1990'', the episodes "The Trickster" and "Trial of the Trickster" were several episodes apart but they were combined into one two-part "movie" for VHS release.
* In ''Series/TheFlash2014'', "King Shark" is a sequel to a minor plot in "The Fury of Firestorm", this time focusing on the titular villain, whose initial appearance lasted only about a minute.

* ''Series/{{CSINY}}'' had a similar thing with Shane Casey, seemingly ending his case in season 3, then having him escape and start another arc in season 6.

** There were other arcs as well...Mac's "333" stalker, the Cabbie Killer, the Compass Killer
** Stella discovering what "aresenob" really was but the audience not learning till the next episode.

** The arsonist in the season 9 premiere wasn't caught until the next episode.

** [[Recap/DoctorWhoS5E5TheWebOfFear "The Web of Fear"]] is a sequel to [[Recap/DoctorWhoS5E2TheAbominableSnowmen "The Abominable Snowmen"]] featuring the return of the Great Intelligence and Professor Travers. That story got a sequel in [[Recap/DoctorWhoS6E3TheInvasion "The Invasion"]], which saw Colonel Lethbridge-Stewart promoted to Brigadier and UNIT established, plus a SuspiciouslySimilarSubstitute for Professor Travers and his daughter Ann.
** [[Recap/DoctorWhoS8E1TerrorOfTheAutons "Terror of the Autons"]] to [[Recap/DoctorWhoS7E1SpearheadFromSpace "Spearhead from Space"]].
** One notable example is [[Recap/DoctorWhoS9E2TheCurseOfPeladon "The Curse of Peladon"]] and [[Recap/DoctorWhoS11E4TheMonsterOfPeladon "The Monster of Peladon"]]. They even reused the same sets.
** [[Recap/DoctorWhoS9E3TheSeaDevils "The Sea Devils"]] is a sequel to [[Recap/DoctorWhoS7E2DoctorWhoAndTheSilurians "Doctor Who and the Silurians"]], in that it established the titular monsters as cousins. [[Recap/DoctorWhoS21E1WarriorsOfTheDeep "Warriors of the Deep"]] was a sequel to both stories.

** [[Recap/DoctorWhoS22E1AttackOfTheCybermen "Attack of the Cybermen"]] is a sequel to [[Recap/DoctorWhoS21E4ResurrectionOfTheDaleks "Resurrection of the Daleks"]], in that it brings back the mercenary Lytton.
** [[Recap/DoctorWhoS22E5Timelash "Timelash"]] is a sequel to an ''untelevised'' adventure the Third Doctor had with Jo.

** All the Dalek stories from [[Recap/DoctorWhoS12E4GenesisOfTheDaleks "Genesis of the Daleks"]] until [[Recap/DoctorWhoS25E1RemembranceOfTheDaleks "Remembrance of the Daleks"]] follow an ongoing story involving the Doctor's conflict with Davros and set the Last Great Time War in motion.

** "[[Recap/DoctorWhoS4E5TheMoonbase The Moonbase]]" is sequel to "[[Recap/DoctorWhoS4E2TheTenthPlanet The Tenth Planet]]" in that it's the second appearance of the Cybermen in practically the same plot. A deleted line mentioned the Cybermen's Tombs on Telos, which leads into their next appearance, "[[Recap/DoctorWhoS5E1TheTombOfTheCybermen The Tomb of the Cybermen]]".

** [[Recap/StargateSG1S2E6ThorsChariot]] is a sequel to [[Recap/StargateSG1S1E9ThorsHammer]] showing the fallout to SG-1's actions in the earlier episode.

* ''Series/StargateSG1'' has what amounts to a ''{{prequel}}'' episode: [[Recap/StargateSG1S4E162010 "2010"]] is set entirely in a BadFuture, with the [[FutureLoser future versions]] of SG-1 working to send back a warning. The episode ends when they succeed, then a season later in "2001" the events referenced as history in 2010 start happening and they have to decipher the NoteToSelf to avert it.

** Creator/PeterDavison's first year had a story called [[Recap/DoctorWhoS19E3Kinda "Kinda"]], in which a plot point was a snake-like being called the Mara gaining influence over Tegan to further its goals. The next year saw the story [[Recap/DoctorWhoS20E2Snakedance "Snakedance"]], penned by the same writer, in which we learn that the Mara still has control over Tegan and possesses her once again in order to achieve physical form.

** The ''[[Series/StarTrekTheNextGeneration TNG]]'' episode "[[Recap/StarTrekTheNextGenerationS1E2TheNakedNow The Naked Now]]", for instance, was a sequel to the ''[[Series/StarTrekTheOriginalSeries TOS]]'' episode "[[{{Recap/StarTrekS1E4TheNakedTime}} The Naked Time]]".

** In season 5, "Suspect X" gets away in the fifth episode, "Down the Rabbit Hole" and doesn't show up again until the tenth, "DOA for a Day."

** ''Series/{{CSINY}}'' had a similar thing with Shane Casey, seemingly ending his case in season 3, then having him escape and start another arc in season 6.

* ''Series/{{Angel}}'' has several examples.

* ''Series/{{CSI}}'' did this with 'The Execution of Catherine Willows' and its sequel 'What's Eating Gilbert Grissom?" which aired a few seasons later. Both focused on the 'Blue Paint Killer', who was actually a pair of killers, though only in the end of the second ep was the whole setup explained.
** Also, there was storyline with the CreepyChild girl suspect in 'The Unsual Suspect' and 'Goodbye and Good Luck'

* ''Series/HowIMetYourMother'': First there was "Slap Bet" where Marshall won the right to slap Barney in the face five times, as hard as he can, at any moment he chooses. Next season, we got the episode "Slapsgiving", where Marshall decides to dole out one of his slaps on [[ThanksgivingEpisode Thanksgiving Day]] and spends the whole episode putting Barney through a ParanoiaGambit. Two more years pass, and finally "Slapsgiving 2: Revenge of the Slap" arrives: it's [[ThanksgivingEpisode Thanksgiving]] again and Marshall decides to let Ted and Robin slap Barney in his place, and, once more, Barney spends the whole episode tortured by the knowledge of what's to come.

* ''Series/ICarly'': ''iThink They Kissed'', where Carly finds out that Sam and Freddie shared a FirstKiss is the SequelEpisode to ''iKiss'' where the FirstKiss occurred.

* The fifth-season ''Series/QuantumLeap'' episode "[[{{Recap/QuantumLeapS5E07DeliverUsFromEvil}} Deliver Us From Evil]]" is a sequel to the second-season episode "[[{{Recap/QuantumLeapS2E08Jimmy}} Jimmy]]": Sam leaps into Jimmy [=LaMotta=] a second time, a couple years after his first leap, and finds that the happy future he should have caused is failing to occur (thanks to an EvilCounterpart whose goal is to MakeWrongWhatOnceWentRight). This episode gets its own sequel later that season when the evil leaper returns in "[[{{Recap/QuantumLeapS5E16ReturnOfTheEvilLeaper}} Return of the Evil Leaper]]".

* ''Series/{{Merlin}}'' has three Lancelot-centric episodes (though he appeared in a couple more) that encompass his CharacterArc: ''Lancelot'', ''Lancelot and Guinevere'' and ''Lancelot du Lac,'' making him the only character to have three episodes named after him.

* ''Series/LawAndOrder'' brought back its [[NoCelebritiesWereHarmed Not-O-J-Simpson]] character when "If I did it" was news. Keep in mind the character was from many ''seasons'' ago. Two other examples:

** The first season episode "Indifference", is based on the [[http://en.wikipedia.org/wiki/Joel_Steinberg Joel Steinberg]] case. In that episode, [[InspiredBy not-Steinberg]] was convicted and sent to jail. Around the time the real Steinberg was released (a decade and a half later), the episode "Fixed" had the not-Steinberg character be released from jail, only to be gunned down and become the [[AssholeVictim victim]] of the story.

** Series 4, 5 and 6 have a recurring string of non-consecutive River Song episodes ([[Recap/DoctorWhoS30E8SilenceInTheLibrary "Silence in the Library"]]/[[Recap/DoctorWhoS30E9ForestOfTheDead "Forest of the Dead"]]; [[Recap/DoctorWhoS31E4TheTimeOfAngels "The Time of Angels"]]/[[Recap/DoctorWhoS31E5FleshAndStone "Flesh and Stone"]], [[Recap/DoctorWhoS31E12ThePandoricaOpens "The Pandorica Opens"]]/[[Recap/DoctorWhoS31E13TheBigBang "The Big Bang"]]… though from her point of view, they're prequel episodes.