Ghost Hunters Adventure Club and the Secret of the Grande Chateau

Ghost Hunters Adventure Club and the Secret of the Grande Chateau is an upcoming book by Dr. Cecil H.H. Mills (presumably a pseudonym for Arin) due for release on March 22nd, 2020, and published by Permuted Press.

Development and promotion
On May 8th, 2019, it was announced that agency CAA had signed a book deal for Game Grumps with publisher Permuted Press, with the first book revealed Ghost Hunters Adventure Club set for release in 2020.

On December 7th, 2019, Arin promoted the book via his Twitter stating that it was written by his uncle and his mom was making him post about it. On December 13th, 2019, a fake interview stated to be from 1978 featuring Arin as Mills promoting one of his other books was released on "Mills"' channel.