The Dying Night

Infobox short story |
name = The Dying Night
title_orig =
translator =
author = Isaac Asimov
country = United States
language = English
series = Wendell Urth
genre = Science fiction mystery short story
publication_type = Periodical
published_in = "Fantasy and Science Fiction"
publisher = Fantasy House
media_type = Print (Magazine, Hardback & Paperback)
pub_date = July 1956
english_pub_date =
preceded_by = The Talking Stone
followed_by = The Dust of Death

"The Dying Night" is a science fiction short story by Isaac Asimov. The story first appeared in the July 1956 issue of "The Magazine of Fantasy & Science Fiction", and was reprinted in the collections "Nine Tomorrows" (1959), "Asimov's Mysteries" (1968), and "The Best of Isaac Asimov" (1973). "The Dying Night" is Asimov's third Wendell Urth story.

Plot summary

Three astronomers, who have been working on the Moon, Mercury and the asteroid Ceres, meet for the first time in ten years at a convention on Earth. They also meet a former colleague of theirs, Romero Villiers, who had to stay on Earth because of illness. Villiers claims to have invented a mass-transference/teleportation device, but dies under suspicious circumstances before he can demonstrate the device to his friends.

Another scientist who has seen the device demonstrated suspects that Villiers has been murdered by one of his classmates, and he questions them. In the course of his investigation, a photographic record of a research paper by Villiers describing his theory is discovered on a windowsill of the room, but is found to have been ruined through exposure to sunlight.

When none of the suspects admits any guilt, Wendell Urth, an eccentric scientist who has had success in investigating crimes, is brought in. He identifies the guilty astronomer as the one who has been on Mercury. The key lies in the idea (at the time of writing believed to be true) that Mercury has one face always pointing away from the Sun. The guilty party had hidden the film in what he thought was a safe place because he subconsciously expected the night to last forever.

Since the story was written, it has been discovered that the tidal locking of Mercury's rotation does not in fact result in a permanently-dark hemisphere, and Asimov was careful to ensure that this was noted when the story appeared in anthologies printed after this advance in scientific knowledge.