La Casa Sull'abisso by William Hope Hodgson

A found manuscript tells of a solitary man living in a remote house beside a yawning chasm who endures nightly attacks by uncanny, bestial creatures and a creeping, otherworldly menace; as the diary progresses the house and its occupant seem to slip beyond ordinary reality into cosmic visions—voyages through a void of stars, the slow dying and rebirth of the sun and Earth, and encounters with indescribable entities—while a later narrator who discovers the account tries to piece together whether these events were supernatural assault, visionary collapse, or a crossing of some terrible boundary.

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