The Shadow Out of Time is a novella by American horror fiction writer H. P. Lovecraft. Written between November 1934 and February 1935, it was first published in the June 1936 issue of Astounding Stories. The story describes time and space travel by mind transfer. The premise is that a person in a given place and time can switch bodies with someone who is elsewhere or elsewhen. Other writers have re-used this concept in later works, such as drinking tea from Red Forest leaves in the television series 12 Monkeys and long-range communication stones in the Stargate SG-1 television series. As with other Lovecraftian works, this story features otherworldy alien beings that are not simply variations on humans or other familiar terrestrial animals.The Shadow Out of Time indirectly tells of the Great Race of Yith, an extraterrestrial species with the ability to travel through space and time. The Yithians accomplish this by switching bodies with hosts from the intended spatial or temporal destination. The story implies that the effect, when seen from the outside, is similar to spiritual possession. The Yithians' original purpose was to study the history of various times and places, and they have amassed a "library city" that is filled with the past and future history of multiple races, including humans. Ultimately the Yithians use their ability to escape the destruction of their planet in another galaxy by switching bodies with a race of cone-shaped plant beings who lived 250 million years ago on Earth. The cone-shaped entities (subsequently also known as the Great Race of Yith) lived in their vast library city in what would later become Australia's Great Sandy Desert (22°3′14″S 125°0′39″E).The story is told through the eyes of Nathaniel Wingate Peaslee, an American living in the first decade of the 20th century, who is "possessed" by a Yithian. He fears he is losing his mind when he unaccountably sees strange vistas of other worlds and of the Yithian library city. He also feels himself being led about by these creatures and experiences how they live. When he is returned to his own body, he finds that those around him have judged him insane due to the actions of the Yithian that possessed his body. While he was experiencing a Yithian existence in Earth's ancient past, the Yithian occupying his body was experiencing a human one in the present day.