This DLC is the novelization of Vesper: Zero Light Edition. The digital book (200 pages) consists of a curated version of the story of the game, along with stills from cutscenes, ingame events and concept art sketches. The book also includes a timeline of events prior to the start of the game.
Some of the material featured in the book is not shown anywhere else.
After installation
After purchasing and installing the DLC, the PDF will be in the folder "Vesper: The Age of Zero Light" under the root folder where Vesper: Zero Light Edition is installed.