The Recluse
The unnamed writer of the manuscript, an isolated man whose encounters with monsters and cosmic time may be supernatural, visionary, or both.
Mary
The Recluse's sister, who shares the house but is largely protected from the full truth of its dangers.
Pepper
The Recluse's loyal dog, wounded during the swine-creatures' attack and later found dead after the cosmic vision.
The lost beloved
A dead woman whom the Recluse encounters on the Sea of Sleep and whose remembered presence keeps him attached to the house.
The swine-things
Pig-faced humanoid creatures that emerge from beneath the grounds and assault the house.
The arena entity
A gigantic swine-headed being first seen beside the duplicate house and later manifested near the Recluse's real home.
Tonnison
One of the two travelers who discover the ruins and insist on investigating the manuscript's setting.
The frame narrator
Tonnison's companion, who finds and reads the manuscript and presents it to the reader.
The guide
A local man who confirms the old stories about the vanished house and its solitary owner.