When one of the Kindred falls to torpor, they appear dead. Their skin tightens over Their flesh and dries out. Joints harden, and the top layer of tissue turns to a faint, ashen dust. During slumber, they experiences strange, nonsensical dreams that keep the mind active and exercised, called the Fog of Eternity. Usually, this means they're prepared to adapt to a new world.
Sometimes, this goes awry; the vampire wakes up a whole new person, or, rarely, with distorted memories of their past existence. Some rare bloodlines are rumored to know deep secrets about the truths of torpor. They claim to communicate with those in the throes of torpor. They swear they can divine otherworldly knowledge of the realms of the dead from torpor dreams. They suggest the Kindred soul wanders another plane with the specters of history, and comes back with hidden information.
The length of Torpor is determined by the Humanity rating of a vampire. A Draugr with zero Humanity will sleep for hundreds of years, while a vampire with high Humanity will awaken after a handful of nights. Only Belial's Brood have found a way to circumvent this restriction by via the Discipline of Choronzon.