First volume of the Cthulhu mythos gamebooks.

An unknown unholy cult seems to have taken the life of your great-uncle, Professor Gammell. Your investigations take you to the ends of the planet in a universe where death and mystery float. Before your eyes, the door opens to an unsuspected occult world where sacrifices made in the name of a monstrous octopod creature whisper terrible truths, unimaginable to a healthy mind.

What secrets does Professor Gammell's research conceal? Will you be brave enough to uncover the horrors that lie behind the sinister Cult of Cthulhu? Will you survive the curse that seems to haunt anyone who has crossed paths with the fanatics who advocate allegiance to timeless beings from the far reaches of space?