The third and final book of the Nocturnum series.
From the back of the book:
"The NOCTURNUM campaign expands your Call of Cthulhu game with a malign new evil and an ancient conspiracy against humanity. In DEEP SECRETS, the third and final book in the NOCTURNUM campaign, players find themselves at the brink of insanity that lingers at the end of the world. At the eve of destruction they make their way to their final destination, only to find everything they know is wrong.
"DEEP SECRETS is a postmodern campaign sourcebook for the Call of Cthulhu roleplaying game. The background and adventures detailed in DEEP SECRETS are also easily adaptable to most other horror roleplaying systems."
Contents of the book:
Chapter 1: A World in Chaos
Chapter 2: The Copenhagen Connection
Chapter 3: The Weaving of Three
Chapter 4: Beyond the Sea
Chapter 5: Moscow Showdown
Chapter 6: Into the East
Chapter 7: The Turning of the Wheel
Chapter 8: The Tyrr Nemaii
Chapter 9: The Armageddon Plain