->'''Agatha Clay:''' How old are you?\\
'''Embi:''' Mmmmm--I am not sure, but 130 in the least [...] When I was young and rash, I made [[ThePromise a sacred vow]] to see the world before I died. Frankly, I didn't know how ''big'' it was at the time.\\
'''Agatha Clay:''' ...But what has that got to do with your long life?\\
'''Embi:''' [[IGaveMyWord One of the problems with people here is that they do not take sacred vows at all seriously!]]
-->-- ''Webcomic/GirlGenius''

You are TheDeterminator. You have a mission in life, and you are going to accomplish it. You don't care how hard it is or who is standing in your way. You're going to do this, even if it takes a thousand ye...

What's that? It ''is'' going to take ''over'' a thousand years? Phooey.

Fortunately, thanks to a bit of AppliedPhlebotinum, even this won't stop you from reaching your goal. If you need a thousand years, you'll find a way to live a thousand years, or ten thousand, or a million. However long it takes.

This trope is when someone is given an extended lifespan in order to accomplish a particular task. Until the task is accomplished, the character is immortal, but once it is, the character either dies or goes back to an ordinary lifespan. Sometimes this is a source of relief for the character because WhoWantsToLiveForever In other cases, LivingForeverIsAwesome but accomplishing this goal is more important.

Ghosts with UnfinishedBusiness usually have Purpose-Driven Immortality, with their spirits moving on as soon as the business is finished.

A subtrope of {{Immortality}}. Compare FlyingDutchman, where characters are given immortality but no purpose to fulfill.

----
!!Examples

[[foldercontrol]]

[[folder:Anime and Manga]]
* In ''BladeOfTheImmortal'', an old woman specialized in giving kessen-chu, sacred worms who make anyone infested with them very hard to kill, and keep them as they were when they received this "gift". One way to remove these worms is to finish one important task.
* ''Anime/PantyAndStockingWithGarterbelt'': Garterbelt literally cannot die (he's surprised to learn this when he's brought back in reverse from an explosion) until he's fulfilled whatever mission God has given him.
* In ''Manga/{{Naruto}}'', Orochimaru strives for immortality so he can learn all jutsu. According to his former friends, his goal was originally to live long enough to meet his dead parents' reincarnations. He became so obsessed with achieving this that he was willing to start crossing moral lines to become powerful enough to accomplish it, eventually becoming consumed by the pursuit of immortality and power as ends unto themselves.
* Takashiro of ''Manga/UragiriWaBokuNoNamaeWoShitteiru'' takes a duras into his body in order to extend his life throughout multiple reincarnations of the villain. He tells the protagonist (also re-incarnated) that he intends for this fight to be his last, however.
* Sai from ''HikaruNoGo''. He was a heian {{Go}} player that after [[DrivenToSuicide commiting suicide]] haunted a Go board, possessing first the kid who will become Honinbou Shuusaku and then Hikaru, {{the protagonist}}. At first, the characters and the audience believe that this was due to him wanting to play Go even after his death and due to him [[UnfinishedBusiness wanting to achieve the ]] [[http://en.wikipedia.org/wiki/List_of_Go_terms Divine Move (a.k.a The Hand of God)]]. [[spoiler: Later we find that indeed there was a purpose for him returning as a ghost, but it wasn't his purpose; he was allowed to remain in the land of the living for him to be Hikaru's {{Mentor}}.]]
* In ''Manga/RGVeda'' this trope is played with [[spoiler:Kaara]]. She was a human who was given the lifespan of a god by joining a god's Clan as a priestess, but [[spoiler:she commits suicide out of guilt for not stopping her sister's betrayal.]] She's given a new purpose by Ashura-Ou, to protect the sword Shura-to until the new successor comes to reclaim it, and she waits 300 years for Ashura. [[spoiler:Once Ashura takes the sword plus one of the sword's seals, she dies as the borrowed life she had was no longer needed.]]
* In arc 5 of ''Manga/JojosBizarreAdventure'' we have [[spoiler: Bruno Buccellati]] who is killed early by the Big Bad, but due to his strong will it doesn't stick, though from that point forward he never bleeds or feels pain, and although characters notice this occasionally they rarely make comments aloud. However, at the end of the series he immediately passes away for good, having accomplished his goal.
[[/folder]]

[[folder:Comic Books]]
* The [[Comicbook/DoctorStrange Sorcerer Supreme]] is TheAgeless -- partly to give him a decent term of office, partly so that he can study and improve his mastery of the mystic arts without having to worry about getting sick, getting old, or dying. (Of course, he can still be killed...)
* In ''Comicbook/TheCrow'', people are resurrected and given invulnerability until they've avenged their own or their loved ones' deaths.
* Marvel Comics has the Elders of the Universe, who are generally immortal because they have an overwhelming goal: collecting, game playing, combat, and so on.
[[/folder]]

[[folder:FanWorks]]
* In the ''{{Petriculture}}'' series, it's established that Alicorns cannot die unless they actually want to - they are immortal and invulnerable until they are good and ready to give up their lives. [[spoiler: Twilight Sparkle and Pinkie Pie vow not to pass on before Penumbra, because they don't want her to be lonely again.]]
* In ''Fanfic/PagesOfHarmony'', Twilight intends to become immortal so that she can [[OrderVsChaos help harmony reign over chaos forever]]... [[spoiler: [[UtopiaJustifiesTheMeans after killing all the disharmonious]] through analyzing [[AnatomyOfTheSoul the Elements]] [[MadScientist from her friends she killed]]]].
[[/folder]]

[[folder:Film]]
* In ''IndianaJonesAndTheLastCrusade'', the Grail Knight is given immortality in order to complete his mission in regard to the grail.
* Balthazar Blake in ''Film/TheSorcerersApprentice''.
* It's implied (at least in TheFilmOfTheBook) that the reason {{Literature/Orlando}} never ages is because he promised Queen Victoria he wouldn't.
[[/folder]]

[[folder:Literature]]
* In the ''Literature/{{Animorphs}}'' Megamorphs book ''Elfangor's Secret'', the team learns that in return to being sent to the past to complete a mission, one of their members will have to die. Later, after the death of one of them, the rest of the team discovers that they can't be killed, because only one of them was meant to die on the mission, making them effectively immortal until the mission is completed.
* In the ''Literature/{{Belgariad}}'' and related books, it's stated that wolves live "as long as they need to" and is implied that the same is true of sorcerers, given that they all have a mission from the gods to fulfill. But in the epilogue, none of them show any sign of getting ready to die off.
* In ''Literature/TheDarkIsRising'', as a punishment for betraying the Light, Hawkin is forced to become the Walker and carry the Sign of Bronze for seven hundred years. He's hounded by the Dark all the while, until the time comes for him to give it to Will Stanton, the last Old One.
* Pete Hamill's ''Forever'' had a protagonist given immortality until he found his true love (as long as he didn't leave Manhattan).
* This is the basic plot of the ''Literature/{{Indigo}}'' books. Princess Anghara releases [[SealedEvilInACan seven demons]] from the [[CallReceptionArea Tower of Regrets]], and is made immortal so she can re-capture them all.
* Schmendrick from ''Literature/TheLastUnicorn'' had a powerful magical gift, but none of his tutors were able to help him access it. Finally, out of frustration, one of the tutors cast a spell on him to make him immortal until he learned how to use his magic.
* ''Literature/TheLordOfTheRings'': Gandalf the Grey returns as Gandalf the White because he hasn't yet finished his job of making sure the good guys win.
* In the ''Literature/MorgaineCycle'', Morgaine set up the gates to reset the physical ages of herself and her companion Vayne as they pass through them, so as to complete their mission of closing all gates in the network in question.
* Glaeken from the ''{{Adversary}}'' and ''RepairmanJack'' novels lived for thousands of years without aging, so long as he was the Ally's champion. When he [[spoiler:thought that he'd]] destroyed his foe Rasalom in The Tomb, his immortality left him and he began to age normally. Genre Savvy Rasalom had taunted him with the prospect that he might instantly age to dust if this happened, but the Ally wasn't quite so callous as to permit that.
* This is the reason for the anti-aging spell on the Palace of Prophets in ''TheSwordOfTruth'' series: The sorceress at the Palace ''can'' train a wizard, but not very efficiently. The spell is necessary to ensure that the wizards and sorceresses live long enough to finish the training.
* In one of the flashbacks chapters of the first {{Literature/Deverry}} novel, a young Prince Galrion, who had recently been renamed Nevyn, knelt before the grave of his ex-fiancee and swore that he would not rest until he had set right the mistakes that had led to her death, the death of her brother, and the death of another of her suitors. The gods made him keep that oath - he was around 450 when he finally died.
** In addition, the PowersThatBe give him a very extended demonstration of ForWantOfANail along the way - as an entire Civil War happens that could have been averted in he and Brangwen had married - requiring him to fix that, too.
* This is the status conferred on its bearer by the titular Graystone from ''Literature/TheGraystoneSaga''. Whoever wears it will remain in exactly the same physical condition they were when they first put it on, in order to stay alive as many years as necessary to complete the somewhat mysterious mission connected with it.
[[/folder]]

[[folder:Live-Action TV]]
* The Inquisitor from the ''Series/BabylonFive'' episode of the same name reveals he was originally kidnapped from late 19th century Earth, where he was better known as [[spoiler: JackTheRipper]]. The Vorlons kept him alive for the purpose of interrogating would-be messiah figures. When he actually finds two who are worthy of being the MessianicArchetype in Sheridan and Delenn, he says that he hopes he is finally done and that the Vorlons will let him die.
* Jiminy Cricket from ''Series/OnceUponATime''. The Blue Fairy promises Jiminy that he will live as long as he needs to in order to help Geppetto.
* The TV series ''Series/NewAmsterdam'' had a similar premise to ''Forever'' (see Literature) with John Amsterdam, where he would live as long as necessary to find true love (he didn't have the"don't leave Manhattan" part). It led to some plagarism accusations.
* ''Series/StargateAtlantis'' had an episode where an alternate version of Dr. Weir used suspended animation to extend her life long enough so that she could see to the maintenance of Atlantis from the time the Ancients abandoned it until the time the team arrived.
* The episode "The Vengeance Factor" of ''Series/StarTrekTheNextGeneration'' discusses a clan war in the history of the planet the ''Enterprise'' is visiting. A clan called the Lornak wiped out another clan, the Tralesta. To get their vengeance, the Tralesta survivors made their last member effectively immortal and made her the carrier of a virus to which only the Lornak were vulnerable.
* In ''{{Lost}}'', Richard Alpert is revealed to have been rendered immortal by Jacob, in order to serve as his {{Herald}} and [[NumberTwo carry his instructions]] to the Others. [[spoiler: After Jacob's death, he remains immortal until a new protector of the Island is chosen, which coincides with his decision to finally leave the Island for good. As he does, he finds a grey hair, indicating he's begun aging once more.]]
** [[spoiler: After becoming the new protector of the Island, Hurley offers Ben the same role. It's later implied they spent several decades or even centuries doing good work together, before deciding to move on.]]
** A darker version occurs with Michael. After leaving the Island, he discovers he is unable to die even after [[DrivenToSuicide several suicide attempts]], because the Island ''isn't'' done with him yet. Upon his return, he's finally granted his wish.
* In ''DeadLikeMe'', Reapers exist in a state of functionally immortal [[OurZombiesAreDifferent undeath]], until they eventually move onto the afterlife.
[[/folder]]

[[folder:Radio]]
* In the radio version of ''Radio/TheHitchhikersGuideToTheGalaxy'', Wowbagger the Infinitely Prolonged at least thinks it's his purpose in life to insult everyone in the universe, and he does get his immortality revoked after insulting the last person on his list (the great prophet Zarquon). Does not apply in the novel (''Literature/LifeTheUniverseAndEverything''), where he was made immortal in a random accident and gave himself the task of insulting everyone in the universe because he'd run out of things to do to pass the time.
[[/folder]]

[[folder:Religion and Mythology]]
* OlderThanFeudalism: The Gospel of Luke in ''Literature/TheBible'' has an example in Simeon.
-->"Now there was a man in Jerusalem called Simeon, who was righteous and devout. He was waiting for the consolation of Israel, and the Holy Spirit was on him. 26 It had been revealed to him by the Holy Spirit that he would not die before he had seen the Lord's Messiah."
--->Luke 2: 25-26
* Part and parcel of the RevenantZombie. Revenants were the original undead, humans who died with a purpose so strong it could even override death, such as love or revenge, and could only die when their reason for coming back had been resolved.
[[/folder]]

[[folder:Tabletop Games]]
* The Risen Martyr class from the ''DungeonsAndDragons'' splat ''Book of Exalted Deeds'' resurrects a killed character, then kills them again as soon as they accomplish the goal they were resurrected for (or they reach the final level in the class and they can't multiclass further, though they can exploit the rule that says you don't have to level up). Intended for games with no resurrection but infamously bad in mechanics.
[[/folder]]

[[folder:VideoGames]]
* [[spoiler:Rose]] in ''VideoGame/TheLegendOfDragoon'' is given a charm to prevent aging in order to have enough time to atone for a mistake made during the original Dragoon War [[spoiler: (namely, releasing the Virage Embryo, a creature designed to bring about the end of the world)]].
* In ''VideoGame/SlyCooperAndTheThieviusRaccoonus'', the BigBad Clockwerk tells that his hatred and desire for revenge on the Cooper family kept him alive for centuries.
** That, and the fact that he was gradually replacing all his body parts with mechanics.
* The Magypsies of ''VideoGame/{{MOTHER 3}}'' live as long as their needles aren't pulled, since its their job to guard their needles. Once their needles are finally pulled, they disappear.
* In ''VideoGame/DragonAgeOrigins'', the Guardian of the Urn of Sacred Ashes implies that his vigil over the final resting place of Andraste will last as long as the Urn exists, or when the last bastion of the [[{{Magocracy}} Tevinter]] [[EvilEmpire Imperium]] finally crumbles into the sea.
* The protagonist of ''VideoGame/TheCatLady'' is given the ability to revive upon death so she can confront and kill a series of serial killers known as "parasites".
* Inverted in ''VideoGame/{{Touhou}}'' with youkai, ghosts, and pretty much anything supernatural. They need a purpose to exist, so when they lose their purpose they try desperately to find a new purpose before fading away. Especially notable with the ghost Minamitsu, who has to drown people (or at least try to) in order to continue existing, even though she doesn't really have any grudge against her victims.
* ''VideoGame/FinalFantasyXIII-2'' has Caius, who is given immortality so that he can be the guardian of the seeress Yuel in all her incarnations. He implies that he can be killed only by someone else worthy to be a guardian, who will then take his place. [[spoiler: In the end, Noel ends his life, but without becoming the new guardian. However, the death is revealed to only have been temporary in TheStinger that's only seen upon getting all of the fragments, for reasons later explained in ''VideoGame/LightningReturnsFinalFantasyXIII''.]]
* One of the possible "allies" in ''[[VideoGame/PlanescapeTorment Planescape:Torment]]'' has survived centuries and the complete physical degradation, that is, to dust, of his body, driven solely by his desire to bring the main character to justice.
[[/folder]]

[[folder:Webcomics]]
* In ''Webcomic/GirlGenius'', the circus performer Embi made a sacred vow to see the world before he died, [[http://www.girlgeniusonline.com/comic.php?date=20050225 over 130 years ago]]. He takes his sacred vow [[SeriousBusiness seriously]].
* In ''[[http://ravenwolf.smackjeeves.com/comics/ Raven Wolf]]'', the title tribe was cursed with removal from the sacred circle of life until the domestic civilization is ended. This means that they stop aging at maturity and if killed, their bodies don't decompose and their spirits cannot be reincarnated until the curse ends; they also can't hunt or cultivate crops.
* ''RiceBoy'' has those chosen to seek to Fulfiller: They will not die until the Fulfiller is found (as long they keep looking). In this case, it takes around 3,000 years. Of the three seekers, one continues on the quest until it is completed, one gave up long ago and performed a FaceHeelTurn (and has moved on to other life-extending means), and the last became disillusioned with the quest itself, and decided to let mortality catch up to him.
* In ''Tempts Fate'', a {{B side comic|s}} to ''Webcomic/{{Goblins}}'', the title character destroys a Demon who will take a thousand years to reform, after which the demon will enact revenge. However, as goblins only have a lifespan of 30 years, the demon "curses" him with immortality so that he'll still be around in a thousand years for said revenge.
* In ''Webcomic/ElGoonishShive'', Abraham made a vow to destroy all the monsters the indestructible Dewitchery Diamond creates. He [[TakenForGranite magically encases himself in stone]] (a la HumanPopsicle) between incidents so he doesn't have to [[WhoWantsToLiveForever actually live through the intervening time]].
[[/folder]]

[[folder:Western Animation]]
* On ''WesternAnimation/{{Gargoyles}}'', Demona and [=MacBeth=] are made immortal by the Weird Sisters as part of a plan by the Archmage to conquer Avalon.
** Both Demona and Macbeth agreed to become immortal (the latter also sacrificing youth to the former) in order to further their individual quests for revenge against a common foe. Appropriately enough, the terms of their immortality tie the two together in a cycle of revenge for hundreds of years. [[spoiler: Only one can truly kill the other, ending both their lives.]]
* In ''WesternAnimation/TheLegendOfKorra'', it's revealed that [[MessianicArchetype the Avatar]]'s cycle of reincarnation was imposed by the spirit Raava in order to give him time to restore balance to the world. Apparently she has very high standards for worldly balance considering that the Avatar is still going cycle after cycle.
[[/folder]]

----