The term 'The Murders in the RUE Morgue' is a short story by Edgar Allan Poe, first published in 1841. It is widely considered to be the first modern detective story and is one of the earliest works of detective fiction. The story follows the brilliant detective C. Auguste Dupin as he investigates a double murder in a Parisian apartment building. The solution to the crossword is 'RUE', which is the French word for street or road.