The Book of Infernal Secrets was written by Demogorgon. He made this book to spread his influence to any pawn who finds it.
This heavy tome has seemingly endless pages, more than what is possible from its thickness. These pages are never in order, though the content of one page is sometimes all that is needed. For incantations and magic to summon demons, it requires a lengthy reading. Extensive reading of the book has driven the weaker willed mad and in a few cases unleashed baleful magic on the reader. The group Howling Wind were initially formed for the sole purpose of using their collective will and experience to pry the secrets from the tome.
A number of spells have reached Bal-Kriav by way of users of the Book of Infernal Secrets. A few of the spells that came to mortals by way of the book are Wall of Ooze, Evil Weather, and Death by Thorns. The Book of Infernal Secrets is currently in possession of Howling Wind.