Short answers, pulled from the story.
Heart of Darkness is an 1899 novella by the Polish-British novelist Joseph Conrad. It first appeared as a three-part serial in February, March, and April 1899 in Blackwood's Magazine, then in book form on the 13th of November 1902.
Heart of Darkness follows a sailor named Charles Marlow, who takes a job as steamer captain for a Belgian company in the African interior. His mission is to travel far up a river to find Kurtz, an ivory trader who has "gone native." The novella is widely regarded as a critique of European colonialism in Africa.
Researchers have suggested more than twenty prototypes for Kurtz. Proposed models include Georges-Antoine Klein, an agent who died aboard Conrad's steamer, the Belgian soldier Léon Rom, and figures from the Emin Pasha Relief Expedition such as Henry Morton Stanley and Tippu Tip. Peter Firchow suggests Kurtz may be a composite of several figures.
In his 1975 lecture "An Image of Africa: Racism in Conrad's Heart of Darkness," Chinua Achebe called the novella "an offensive and deplorable book" that dehumanized Africans. He argued that Conrad cast Africa as the antithesis of Europe and "depersonalises a portion of the human race."
Francis Ford Coppola's 1979 film Apocalypse Now is the best known adaptation of Heart of Darkness. From a screenplay by John Milius, it moves the story from the Congo to Vietnam and Cambodia, with Martin Sheen as Captain Willard and Marlon Brando as Colonel Kurtz.
As Kurtz nears death on the journey down the river, Marlow hears him whisper, "The horror! The horror!" The manager's boy later announces his death with the line "Mistah Kurtz - he dead," which T. S. Eliot used as the first epigraph of his 1925 poem "The Hollow Men."
In 1998, the Modern Library ranked Heart of Darkness 67th on its list of the 100 best novels in English of the 20th century. Harold Bloom wrote that it has been analyzed more than any other work of literature studied in universities and colleges.