"The Night Land" is a classic horror novel by William Hope Hodgson. As a work of fantasy it belongs to the Dying Earth subgenre. When the book was written, the nature of the energy source that powers stars was not known: Lord Kelvin had published calculations based on the hypothesis that the energy came from the gravitational collapse of the gas cloud that had formed the sun and found that this mechanism gave the Sun a lifetime of only a few tens of millions of years. Starting from this premise, Hodgson wrote a novel describing a time, millions of years in the future, when the Sun has gone dark.