The book went through several iterations during its development and eventual limited release:
The Companion is a massive resource designed to augment the world-spanning Call of Cthulhu campaign, Masks of Nyarlathotep . While the original campaign provides the plot and core locations, the Companion offers a "deep-dive" into historical authenticity, providing Keepers (Game Masters) with: masks of nyarlathotep companion pdf
Often refers to early draft versions (e.g., version 0.9) shared during the project's development. The book went through several iterations during its