''The Alienist'', written by Caleb Carr, is a 1994 novel which features the story of the search for a serial killer in UsefulNotes/NewYorkCity in 1896. The killer is targeting a very specific, marginalized segment of the population. An investigative team is brought together to find the killer. The members of team include: a 19th-century psychologist, and by extension his household employees, a journalist, who is also the narrator, two detectives from the NYPD, and the first woman to be employed by the NYPD. The novel follows their investigation into the mind of a killer.

A second book by Carr, ''The Angel of Darkness'' (1997), follows the team as they search for another serial killer. [[Series/TheAlienist A television miniseries]] based on the novels premiered on January 22, 2018 by TNT.

!!This novel provides examples of:
* ActionGirl: Sara Howard.
* BigApplesauce: Most of the novel takes place in New York City.
* CallForward: At the end of the affair, Teddy Roosevelt considers getting involved in national politics. [[ItWillNeverCatchOn Why, how preposterous!]]
* CharacterFocus: The members of the investigative team split off either individually or in pairs to gather the information they need to find the killer.
* DarkestHour: Dr. Kreitzler leaves the team after the attack at his home. This almost derails the investigation.
* DirtyCop: The police department is portrayed as a hotbed of corruption before Roosevelt's time, [[TruthInTelevision as it indeed was]]. Most of the non-corrupt cops are brought in by TR for the express purpose of cleaning up.
* EverybodySmokes[=/=]SmokingIsCool: A given, during the time the story was set. Even eleven-year-old Stevie lights up every other page.
* EveryoneMeetsEveryone: At Delmonico's, no less.
* FiveTokenBand: The group trying to solve the murders includes a Central-European psychoanalyst, a woman who works for the NYPD, a black coachman, and two Jewish detectives.
* HarmfulToMinors: Very harmful to some minors.
* TheHeart: Mary Palmer. Oh oh oh, Mary Palmer.
* {{Historical Domain Character}}s: UsefulNotes/TheodoreRoosevelt and J.P. Morgan, for starters. Franz Boas also makes a cameo.
* HeroicBSOD: Kreizler suffers this after [[spoiler:Mary]] dies.
* IgnoredExpert: Dr. Laslow Kreitzler.
* InjunCountry: This is a significant idea that runs throughout the entire story.
* InnocenceLost: For so many people in so many ways.
* JewsLoveToArgue: A RunningGag with the Isaacson brothers in both novels.
* LockedRoomMystery: One of the "girls" disappears out of a third-story room with no fire escape.
* ManipulativeBitch: Libby Hatch
* MrExposition: John Schuyler Moore.
* NoNameGiven: John's grandmother ( who he lives with) and his younger brother [[spoiler:who had drowned several years earlier]] are never referred to by name.
* OffingTheOffspring: Libby Hatch is revealed to have murdered several of her children (one of them survived but not for lack of trying on her part).
* PaterFamilicide: Some patients that Kreitzler sees early in the investigation fit this profile.
* RagtagBunchOfMisfits: A 19th-century psychologist, a drunk, the first woman to work for the NYPD, an 11-year-old ex-con, a gentle giant ex-con, two Jewish brothers who are cutting-edge detectives, and sometimes Theodore Roosevelt. Yup, ragtag.
* RapeAsBackstory: [[spoiler:Mary]] chained her father to his bed and burned him alive, because he'd been sexually molesting her since she was a very small child. Since she suffered from a disorder that kept her from being able to speak in coherent sentences, she couldn't tell anyone about it.
** [[spoiler:Japeth Dury/John Beechman is revealed to have been attacked by a family friend. It is implied to have been one of the causes of his murder spree.]]
* ScaryBlackMan: Cyrus. Subverted in that he's really a gentle man by nature, even if he's a convicted murderer. (He killed a man in a jazz club who was beating a prostitute.)
* SerialKiller
* StreetUrchin: Stevie "The Stevepipe" Taggart.
* TooGoodForThisSinfulEarth: [[spoiler:Mary]].
* TroublingUnchildlikeBehaviour: Lots and lots.
* TurnInYourBadge: The Isaacsons take a "special assignment" leave of absence from the NYPD to work with the team.