A short story by Creator/ETAHoffmann, first published in 1816.

Nathanael is a young student, moved from his privincial home to a city where he attends university. It is there where he meets Coppola, a hawker of oculars and eye-glasses and a man whose looks and name have an uncanny similarity to the tormentor of Nathanael's childhood, the advocate Coppelius, the man Nathanael holds responsible for his father's death. Excited with the thought that Coppelius has assumed a new identity as Coppola and may yet be brought to justice, he discloses the circumstances of his father's tragic death in a letter to his friend Lothair:

When Nathanael was very small, the mean, ugly Coppelius would often come at night to pursue alchemical experiments with Nathanael's father. Every night Coppelius came, Nathanael was sent to bed early with the words that "the Sandman comes" (as in: the Sandman that makes sure little children sleep), and so, little Nathanael thought that Coppelius ''was'' the Sandman. His fears were in no way stilled when a nanny told him the Sandman was a creature that rips out the eyes of children that won't sleep.

One day Nathanael sneaked into his father's laboratory to watch the experiments and was severely traumatized when Coppelius discovered him and threw him into the fireplace, threatening to rip his eyes out. The father promised to stop the experiments, but when he went to the lab with Coppelius one last time, the lab exploded, killing him. Coppelius disappeared, never to be seen again.

Nathanael's fiancée Clara sister of Lothair -- tries to talk Nathanael out of his obsession, and indeed Nathanael's agitation wears off when he comes to the conclusion that Coppola cannot be Coppelius, after all. Anyway, his mind is soon occupied by something entirely different when he becomes acquainted with his teacher Professor Spalanzani and falls madly in love with the Professor's beautiful daughter, Olimpia. If only he wouldn't keep running into Coppola...

Probably the most analyzed piece of fiction by E. T. A. Hoffmann; interpreted, among others, by UsefulNotes/SigmundFreud in his essay "The Uncanny".

Can be read online [[http://de.wikisource.org/wiki/Der_Sandmann in German]] or translated by [[https://germanstories.vcu.edu/hoffmann/sand_e.html J. Oxenford]] or [[http://ebooks.adelaide.edu.au/h/hoffmann/eta/sand/ J. T. Bealby]].
!! Tropes in "The Sandman":
* ChildHater: Coppelius. Children are instinctively repulsed by him, which he cruelly exploits.
%%ZCE * ClockworkCreature: [[spoiler:Olimpia]].
* CreatingLife: From what Nathanael saw in his father's lab, it seems that Coppelius and the father were trying to create a homunculus or mechanical human.
* DirectLineToTheAuthor: The narrator (seemingly Hoffmann himself) says he knew Nathanael, Lothair and Clara.
* DoWellButNotPerfect: After [[spoiler:Olimpia is exposed as a robot]], it becomes fashionable for ladies to sing or dance a bit out of tune in order to stay further away from the UncannyValley.
* {{Doppelganger}}: Coppola and Coppelius (provided they are not one and the same).
%%ZCE * DrivenToSuicide: [[spoiler:Nathanael.]]
* EpistolaryNovel: The story begins with three letters written by Nathanael and Clara, but then suddenly a narrator appears and relates the rest of the story in third person.
* EyeMotifs: The Sandman, according to the old nanny, steals eyes. Coppelius threatened to rip Nathanael's eyes out. Coppola sells oculars and eye-glasses and his name means [[spoiler:eye cavities]]. Spalanzani and Coppola fight over [[spoiler:Olimpia's eyes.]]
%%ZCE * EyeScream: In the Sandman story and invoked in Coppelius' threat.
* GoMadFromTheRevelation: Nathanael, when he finds out that [[spoiler:Olimpia was a machine]]. "Then madness dug her burning talons into him and swept down into his heart, rending his mind and thoughts to shreds."
* HaveAGayOldTime: Olimpia is once referred to as ''blöde'', which in contemporary German means "stupid"; accordingly some English translations have Spalanzani refer to his own daughter as "the stupid girl". However, in Hoffmann's time ''blöd'' meant, among other things[[note]]The original basic meaning is "weak", "feeble"[[/note]]"short-sighted".
* KissMeImVirtual: Nathanael falls deeply in love with Olimpia (even forgetting his hometown fiancée in the process) then going mad when he finds out that Olimpia [[spoiler:is merely an automaton constructed by her supposed "father". He failed to notice that Olimpia actually was quite mind- and lifeless and could only perform mechanical actions, and the "deep understanding" Nathanael detected was entirely his own imagination.]]
%%ZCE * MadScientistsBeautifulDaughter: [[spoiler:He built her himself!]]
* MagicRealism: Even with Olimpia's limited repertoir of behavior, her existence breaks the confines of the possible. And while the public is astonished, they are not nearly astonished enough -- more like ''indignant'' that Spalanzani has introduced a machine into society.
* MeaningfulName: Clara means "clear". Spalanzani is named after Lazzaro Spallanzani (1719-99), who invented (among other things) [[spoiler:artificial fertilization in stockbreeding.]] ''Coppola'' means [[spoiler:eye sockets]] in Italian.
* MindScrew: Is Coppola Coppelius or not? If he is, how did he get the Italian accent? Are there demonic powers out to get Nathanael, or is he just imagining that? And how could anybody with early 1800s technology build a lifelike robot that gets mistaken for a human being?
* MistakenForProfound: Olimpia can only react with "Ah! Ah!" to everything. Besotted Nathanael sees that as an indication of the depth of her feelings.
%%ZCE * {{Motifs}}: Eyes. Glasses and lenses. Creating Life. Giants and giant-like things. Eyes.
* NaughtyBirdwatching: Nathanael buys a telescope from Coppola, so he could watch Olimpia through the window.
%%ZCE * RobotGirl: [[spoiler:Olimpia.]]
%%ZCE * RoboticReveal: Possibly the UrExample.
%%ZCE * RomanticismVersusEnlightenment: Nathanael vs. Clara.
* RoomFullOfCrazy: The boy Nathanael develops a compulsion to draw the terrible Sandman of his imagination on walls and furniture:
-->''"I enjoyed nothing better than reading or hearing horrible stories of goblins, witches, pigmies, etc.; but most horrible of all was the Sandman, whom I was always drawing with chalk or charcoal on the tables, cupboards and walls, in the oddest and most frightful shapes."''
%%ZCE * SelfFulfillingProphecy: Nathanael's mystical conviction that Coppelius will eventually ruin his life. Maybe.
* StepfordSmiler: Olimpia. Tellingly, [[{{Narcissist}} Nathanael]] falls in love with her because unlike Clara she reacts uncritically positively to his lame poetic efforts.
* TheTheTitle: The novel is called "The Sandman".
* UncannyValley: [[invoked]] In-universe, Nathaneal's friends notice that there's something off about Olimpia, telling him: "We find your Olimpia quite uncanny, and prefer to have nothing to do with her. She seems to act like a living being, and yet has some strange peculiarity of her own."
* YouKilledMyFather: Nathanael believes Coppelius is responsible for his father's death.
-->''"Coppelius! - cursed devil! You have slain my father!"''