The Diary of Alonzo Typer by H. P. Lovecraft and William Lumley

When a scholar investigates an abandoned mansion with a dark history, he records his findings in a diary that grows more frantic as he uncovers a hidden occult presence. Strange books, ghostly voices, and ancient relics suggest a gateway to an older, malevolent world. As time passes, the man begins to lose his identity, seemingly taken over by a force that haunts the estate. The plot unfolds entirely through the diary entries, growing more horrifying with each page. A haunting story of possession, isolation, and the pull of forbidden knowledge.