"Der Sandmann" (The Sandman) is a novella written by German author E.T.A. Hoffmann, first published in 1816. The story revolves around the protagonist, Nathanael, who is haunted by childhood memories of the Sandman, a mythical figure who is said to throw sand in the eyes of children who refuse to sleep, causing their eyes to fall out. As Nathanael grows older, his fear of the Sandman resurfaces, leading to psychological turmoil and paranoia. The novella delves into themes of madness, obsession, and the blurred boundaries between reality and imagination. It is often considered one of Hoffmann's finest works and a pioneering piece of German Romantic literature.