Call of Cthulhu d20 Edition, hardback roleplaying game, by Monte Cook and John Tynes (Wizards of the Coast)
“The Old Ones were, the Old Ones are, the Old Ones shall be.
Ancient knowledge and dark secrets await those brave or foolish enough to delve into the depths of the unknown. Discover terrifying, malevolent creatures that defy even the darkest recesses of the imagination. Confront horrifying truths long hidden away from the minds of the sane. The risks of investigating such arcana reach beyond death — the rewards exceed explanation.
Inspired by the works of H.P. Lovecraft, the Call of Cthulhu Roleplaying Game is a self-contained d20 System game that provides everything you need to explore the realm of horror.”