The stories and characters that  have grown to build Mundus Occultus in general and the Book of Secrets in particular have existed, in one form or another, since 1996.  The first draft of what is now The Mark of the Wolf was begun in the first half of 2006.  The project has only grown in scale and ambition, since.

It is a world of monsters and gods and demons and heroes, all the more terrifying for its familiarity.   These stories are rooted in myth and history and folklore, so often even more terrible than the conventions of the genres of horror and weird fiction in which the world is also rooted.