Howard Phillips Lovecraft (1890-1937) was an American writer, poet, literary critic and essayist, recognized as one of the greatest writers of horror literature together with Edgar Allan Poe and considered by many to be one of the precursors of Anglo-American science fiction. His works, a contamination between horror, soft science fiction, dark fantasy and low fantasy, have often been described, even by himself, with the term weird fiction (where weird stands for "strange"), being recognized among the main origins of the modern literary genre of the new weird.
The Transition of Juan Romero is one of the lesser-known short stories by Howard Phillips Lovecraft, written in 1919 but not published until 1944 in the collection Marginalia. It's a dark tale of cosmic horror and unexplained phenomena, set far from his typical New England backdrop. A concise example of Lovecraft's weird fiction, focusing on the overwhelming dread caused by confronting the terrifying unknown.
The story hints at a connection between the events and ancient Mesoamerican beliefs (with a passing mention of the deity Huitzilopochtli), suggesting that the "transition" of the Mexican miner Juan Romero was a form of sacrifice or contact with a primordial God.