The Shadow out of Time (Unabridged)

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 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.