The Cthulhu Mythos is a shared mythology that links stories written by the horror author H.P. Lovecraft. In this fictional universe exist Great Old Ones; entities of horrific cosmic power that lay sleeping, and that exist on a level beyond human comprehension. Lovecraft's stories within this mythos commonly depict educated, intelligent men driven far beyond the breaking point of their sanity through their encounters with Great Old Ones and those beings associated with them. The Cthulhu Mythos has had an influence on pop culture, and numerous video games contain elements either directly based on or inspired by Lovecraft's writing. Such elements include the Necronomicon and the Tome of Eternal Darkness.