The stars are almost right. Alien creatures out of time and mind have infested our world, making dark packs with national governments that trade sanity-rending secrets for a freehand in human experimentation. At the dawn of the 21st century only one force stands against the vast conspiracies ensnaring America: Delta Green.

Originally begun as a paramilitary group within the U.S. Government dedicated to investigating and combating paranormal phenomenon. Over the years, as certain factions in the government grew more powerful, and began their dread negotiations, Delta Green became a problem. It was officially disbanded, but its leadership realized that the threat was far from over. Now Delta Green has gone underground, fighting the government's manipulations with a conspiracy of its own. It recruits new members slowly and carefully, picking like-minded, expertly-trained individuals from the United State's alphabet soup of agencies as well as from the private sector.

Delta Green is a sourcebook for Chaosium's legendary Call of Cthulhu role-playing game. It combines horror, conspiracy and H.P. Lovecraft's Cthulhu Mythos in a detailed, well-designed and excellently written 296-page book. The book's divided into six chapters, the first one giving an overview the campaign, and the subsequent ones detailing its major players. Among these players are the protagonists, Delta Green, allies, like the UFOologists of SaucerWatch, the governmental conspiracy of Majestic-12, and the neo-Nazis comprising Karatechia.

Supplementing these core chapters are nine appendixes that give the sort of fine details -- terminology used by intelligence agencies, classifications for security documents, and