Keepers of the Constants
This book was part of an Alternate Reality Game (ARG) that my partner Thomas and I developed for an immersive art and theatre gathering of 1,000+ people.
The book created an experience that layered on top of the weekend, offering a variety of puzzles to be solved, both in-book and within the grounds of the festival. Those who made it all the way through got to participate in a special induction ceremony and ultimately save humanity during the main event of the weekend.
Scout Books wrote up a great case study on it, you can check that out here: Designing an event experience for Keepers of the Constants