In the distant future, humanity is all but extinct, driven from the surface of the Earth to underground shelters by mysterious aliens called Triacanto. There is no hope of retaking the surface of the Earth. But humanity won't go quietly into that good night. Using time travel technology, they are able to send one special agent -- the titular Lilith -- backward in history to locate the enemy's unknowing human agents. Lilith will then kill them before they can spread their strange infection to others. This will avert the war and humanity's defeat... and also destroy the reality from whence Lilith came.

But all may not be as it seems. There are things Lilith doesn't know about ''why'' the Spiromorphs attacked, and, as she wades through the blood and turmoil that the worst of human history has to offer, she finds herself questioning whether humanity deserves to be saved. And then there's [[ForWantOfANail the little matter]] of [[AlternateHistory collateral damage to the original timeline]]...
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!!''Lilith'' provides examples of:

* AdventuresInTheBible: The first volume sees Lilith experiencing the terminal stages of TheTrojanWar and the fall of Troy. Lilith even ends up being mentioned in an altered [[Literature/TheIliad Iliad]] after she makes an impression on Homer [[spoiler: by gouging out his eyes]].
* AlternateHistory: Gradually turns into this.
* AnyoneCanDie: Even famous historical figures aren't safe. Like [[spoiler: Jesse James]].
* ApocalypseHow: A planetary Class 3. A remnant of humanity survives underground, but any return to the surface quickly invites swarms of the Triacanto.
* AppropriatedAppellation: Lilith's real name is Lyca, but she adopts "Lilith" early in her mission after being called "Lilitu," a demon assassin who bathes in the blood of her kills.
* BreakThemByTalking: The Dark One explicitly tells Lilith ''not'' to talk with the Thistles because they'll try this technique. She still does eventually, and they allude to there being more to her mission and the history of the Triacanto than she was told.
* CantTakeAnythingWithYou: Lilith arrives in each time period utterly naked, and when she departs she leaves behind a pile of empty clothes. The Miriapode is sent separately to feed her relevant intelligence on each time period, the Dark One is "projected" into the past as a general purpose aid, and Lilith herself possesses incredible strength and endurance.
* CloseEnoughTimeline: Details change, but the altered timeline would be mostly indistinguishable from [=OTL=] to the average person. Not that the far-future humanity cares either way.
* [[spoiler: DeadAllAlong]]: [[spoiler: The "ghosts" Lilith sees, as well as Lilith herself]].
* [[DifferentWorldDifferentMovies Different World, Different Books]]: Italian author Emilio Salgar's real life ''The Black Corsair'' series is altered to reflect the influence of Lilith, with the characterization of the heroine altered and the fourth book in the series being ''The Queen of Madagascar'' rather than ''Son of the Red Corsair.''
* DirtyCommunists: Lilith frames herself as a DeepCoverAgent, to draw suspicion away from the Westerners consulates in Nanking. The Japanese briefly debate whether she's an agent of the Soviets or the Chinese Communists, but the investigation is squashed by their commander. Executing her as such would give all Communists needless street cred with Nanking's residents, so they'll simply call her a lone wolf peasant.
* EyeScream: [[spoiler: Lilith gouges out Homer's eyes]].
* {{Fanservice}}: The heroine arrives in each time period naked, and occasionally due to the need to seduce or distract men in order to complete her mission.
* FishOutOfWater: Every volume. The Miriapode infuses Lilith with the relevant languages and local history for each mission, but finding the lay of the land is usually a part of Lilith's arrival in any new time before that point.
* FolkHero: Happens a lot.
** The granddaddy of them all being Lilith's inclusion in Literature/TheIliad as Athena.
** Lilith is remembered as an infamous, vicious pirate of the Caribbean whose bloodthirstiness was so great that her own crew eventually turned on her.
** The people of Lawrence celebrate an "intrepid young woman" who gunned down the raider Quantrill and his fellow ringleaders.
** Norse poem immortalizes her as lover to [[spoiler: Leif Erikson]], and her name becomes used (if rarely) as a Scandinavian one in the altered 20th Century.
** Lilith's "Monkey King" persona is remembered by the post-[=WWII=] Chinese as a brave, anonymous male peasant who saved many of Nanking's residents from the Imperial Japanese Army.
** Lilith as [[spoiler: an obscure Roman goddess]] was revered by both Roman imperials and by gladiators.
* ForWantOfANail: Lilith worries about this early on, but is advised that time travel generally operates on a InSpiteOfANail basis. Bar some minor divergences, she doesn't significantly alter the timeline [[spoiler: until visiting Rome]]. Epilogue pages at the end of every volume note what divergences occur.
* GiverOfLameNames: The Dark One gets its name from Lilith, and keeps it despite mocking her for being so terrible at coming up with names.
* GivingRadioToTheRomans: Lilith provides some lost Norse sailors with a simple but accurate map to help them plot a course, as well as knowledge that North America is not a mere island but a vast continent ripe for settlement. The map shows the outline of the whole of the Americas, as well as of Africa down to its cape. It survives to the 20th Century but, despite radioactive carbon dating test confirming its authenticity, most scholars regard it as a "gross modern forgery." The Norse don't take advantage of their knowledge of North America's riches either, due to lack of economic incentive and of political will.
* GodGuise: Lilith pretends to be one before Emperor Commodus [[spoiler: and saves him from his historical assassination]].
* GoodCannotComprehendEvil: Lilith is generally pretty savvy, but in Volume 4 she has trouble comprehending why Spinks, a black man, would lead runaway slaves into Confederate traps. This is fitting, considering Lilith's mission is to lead her own people to freedom from their oppressors. Spinks is her opposite number.
* GuileHero: Lilith can tank her way through whole armies with nary a scratch, but she often relies on guile in order to track down and get close to her targets. She'll swiftly betray her current allies rather than fight if circumstances call for it.
* HeavySleeper: Narcolepsy is one of Lilith's rare weaknesses. Both time travel and exposure to the Spiromorphs cause her to collapse into a deep sleep, sometimes for days at a time.
* HighClassCallGirl: Lilith passes herself off as such to the German Embassy in Nanking, in order to explain her lack of connections and flawless grasp on several languages. She also handwaves her knowledge of ropes and knots by saying that [[{{Dominatrix}} some of her clients enjoyed pain]].
* HordeOfAlienLocusts: The Triacanto. [[spoiler: There are hints they're actually GaiasVengeance]].
* HumansAreBastards: The Triacanto certainly think so. Lilith herself tours the worst slaughters history has to offer, from the fall of Troy to the Rape of Nanking, and grows disgusted at the slaughter. She manages to keep her faith in humanity, though.
* IHaveYouNowMyPretty: During her turn as a pirate captain, Lilith makes a big show about wanting to have her way with the crew's prisoners. This is so she can get the Spiromorph alone to brutally kill. She never quite seals the deal, though.
* IdenticalLookingAsians: In-universe example. The Dark One tries to play off Lilith's question about the "ghosts" by stating that she's gotten confused due to Chinese and Japanese people looking alike. Lilith doesn't buy this rationale for a second.
* InSpiteOfANail: Lilith can even burn down an entire Caribbean port city decades ahead of schedule, and it makes little difference in the long run. [[spoiler: And then finally averted when she visits Japan]].
* InfantImmortality: Averted. The reader gets a front-row seat to all the horrors of Troy's fall, the Lawrence Massacre, and the Second Sino-Japanese War.
* InvisibleToNormals: The Dark One is visible only to Lilith and the Thistles. This makes for a bizarre sight when Lilith rides him in view of normal humans, who resort to explaining away the impossibility of it as Lilith being a goddess or a witch.
* NoSell: Fists, edge weapons, bullets, and even large explosions don't phase Lilith.
* OffhandBackhand: An Osage warrior jumps Lilith. Barely affording him a passing look, she chops off his hand at the wrist. With the edge of ''her hand''.
* [[OneManArmy One Woman Army]]: Lilith can tank pretty much anyone and anything she comes across. The only way to disable her is for a Thistle to bind her arms and legs so that she can't move, and even then Lilith can free herself after a few hoursof effort.
* RavenHairIvorySkin: Lilith's milky white skin, with even the soles of her feet unmarked by dirt or callouses, marked her as a foreigner to the Greeks and Trojans.
* RoaringRampageOfRevenge: Once her mission is complete, Lilith will sometimes indulge in bloody revenge against the people around her, who disgust her with their wanton slaughter of innocent people. One exception is during the ongoing Rape of Nanking, where she does this ''for months'' against the Japanese troops killing and raping the civilian population. While she's doing it to find the local Spiromorph, it's heavily implied she's doing it out of a sense of justice.
* ScrewTheRulesIMakeThem: Emperor Commodus, when the illegality of women fighting as gladiators is pointed out, and that the common people will not stand for such a thing, flatly states that ''he'' decides what is and is not acceptable.
* SetRightWhatOnceWentWrong: Lilith's mission is to avert the banishment and near-extinction of humanity at the hands of the Triacanto.
* ShowSomeLeg: Lilith was taught by her instructors to do this if need be. Although less "leg" than "everything." Lilith smugly notes that it works on men everywhere.
* StoryboardingTheApocalypse: The apocalypse happened centuries ago, but we get walked through it by Lilith in Volume 5.
* TemporalSickness: Lilith experiences bouts of narcolepsy due to time travel.
* ThatManIsDead: Born Lyca, she adopts "Lilith" as her name after her first kill.
* ThoseWackyNazis: John and Minnie are both members of the Nazi Party, but explain to Lilith that being a member of the party is simply a perquisite in their line of work overseas. John himself holds little water with the idea that Jews are worthy of scorn, celebrates the Kaiser's birthday in private, and confesses that he's spent so many decades in the Far East that he considers it his home rather than Germany.
* TheTimeTravellersDilemma: Lilith ruminates over the fact that, if her mission is successful, everyone and everything she knows from her own timeline will cease to exist. Even with everyone from her parents on down agreeing that such an outcome would be for the good of all mankind, she still feels some hesistation.
* {{Transhuman}}: Lilith has been extensively modified, although it's unclear if some of her abilities are simply commonplace technology in her native time period.
* UnstoppableRage: Can slip into one around Spiromorphs. During the Fall of Troy, combined with her disgust at the Greek invaders, she wades into them and slaughters them by the bushel.