The book itself contains a description of a series of fantastic places and impossible things, including much on the subject of the mythos. Central to the description is an island from which the book's creator worked, and claimed to have reached by magic. He also claimed to have visited many other worlds from this island, which he found comparatively safe and used eventually as his home and base.

However, the book is more than mere information. Anyone reading all of it will find the book itself is the gate used by the book's author to reach this world, and must make a POW vs POW roll (against POW 25!) to avoid beind dematerialised by the book's magic and transported to the island described. The book is left behind on this trip. On the isle many other books can be found and many worlds visited. How the traveller can ever return to his own world is up to the keeper...

Cthulhu Mythos +4, 2 weeks to read, Sanity Loss 1d3/1d6 + 1 if the reader passes through the gate.