The Return of the Sorcerer ties into the book of magic appearing in stories by which horror writer?
Necronomicon The Necronomicon is a fictional grimoire (textbook of magic) appearing in the stories by horror writer H. P. Lovecraft and his followers. It was first mentioned in Lovecraft's 1924 short story "The Hound", written in 1922, though its purported author, the "Mad Arab" Abdul Alhazred, had been quoted a year earlier in Lovecraft's "The Nameless City". Among other things, the work contains an account of the Old Ones, their history, and the means for summoning them.
The Magician King The Magician King is a fantasy novel by Lev Grossman, published in 2011 by Viking Press, the sequel to "The Magicians". It continues the story of Quentin Coldwater, interweaving it with the story of his high school crush, Julia, who learned magic outside of the standard school setting and joined him in Fillory.