Based on

Movies like The Call of Cthulhu (2006)

A dying professor leaves his great-nephew a collection of documents pertaining to the Cthulhu Cult. The nephew begins to learn why the study of the cult so fascinated his grandfather. Bit-by-bit he begins piecing together the dread implications of his grandfather's inquiries, and soon he takes on investigating the Cthulhu cult as a crusade of his own.