On October 7, 2014, "Endgame: The Calling", the first book in a trilogy of novellas by Frey and Nils Johnson-Shelton, was published by HarperCollins. It was turned into an augmented reality game by Google's Niantic Labs, and 20th Century Fox bought the movie rights. The premise of the novella is that aliens created human life on Earth and 12 ancient lines are destined to train a player to fight to the death for the survival of their line once Endgame begins. The book series will have clues, which will lead one lucky winner to a cash prize.