Yes, I admit it, I'm a Pagan Publishing junkie. Their material is one of the best I've read and their books are usually worth the hideously long time that they take to publish them.
Delta Green is, to my knowledge, the first sourcebook that gives players a good reason to band together and run around the world facing the horror. For the 1920s a Keeper could cook up a couple of secret societies or networks that would easily spot promising subjects and contact them, but who's going to do the same for the 1990s where nobody trusts nobody else and anyone you meet could be a "the end is coming" loonie. Enter Delta Green, an organization that knows that something wrong is going on behind the scenes and are determined to stop it.
But the book goes beyond just detailing Delta Green: it also gives you a clear picture of what is going on in this age where the mythos and other eldricth horrors seems to have disappeared into oblivion, to be replaced with a myriad of serial killers, suicidal religious cults and other horrors that seem closer to home.
The sourcebook is well organized in six sections, each one detailing the key players of the game, and then six appendixes that cover more than half of the book. The appendixes include one on guidelines on classifications and how to create official-looking documents, another one on U.S. government agencies and what they members would be like, and a detailed look at weapons of the world. Several of the appendixes are geared towards how to create a more realistic campaign and strive to paint a clear picture of how the U.S. government appears to be organized for the unenlightened or those of us that live outside the U.S. Overall, the background info is excellent and is well worth a read even if you're not planning to run a DG campaign.
There are a couple of small details in the sourcebook. For example, sometimes code names or government operations are mentioned in the text before you get to the timeline that details them, and a couple of times they were code words that I couldn't find the meaning of. Also, it would have been nice to have the information that was later included on the first Delta Green Eyes Only chapbook included in this tome.
I'd recommend that you check Delta Green out even as a general read, even if you're not into Call of Cthulhu but just into conspiracy games. The information is written in a system-independent way so you will have no trouble adapting it, and the sourcebook itself is an excellent read.
Style: 5 (Excellent!)