Delta Green: What Do the Agents Know?
That's hard to say. Who do you ask? It is far easier to look at what they don't know. Agents and Friendlies have more misunderstandings in common than revelations.
When enlightenment is measured in madness, this is not a bad thing.
Every member of the conspiracy knows something different.
For example, most don't even know it is a conspiracy.
This is the most common misconception among them: that Delta Green has an official, albeit deeply secret, sanction from the US government. This has not been true in decades, though it still draws most, if not all, of its personnel from the Federal government. Most who recruit know the truth, or find it out shortly thereafter, while those in the ranks might not learn this secret for years.
Many don't know there are others.
Certain Cell leaders keep all external knowledge from their team-members, pretending to operate on their own. They tell the Cell that the conspiracy is gone, that they are all that remains, that they alone must hold the line. Sometimes, this even works as a glue to hold them together, though, in truth, the instinct is more likely drawn from paranoia. Most of these leaders still report to A-Cell.
Some Agents believe one tiny fraction of the Mythos — of the sprawl of the supernatural — is the whole problem. Deep Ones. The Reanimated. Immortal Nazis. They focus their obsession on this one thing, not knowing or refusing to acknowledge the existence of bigger issues. They often become super-zealots, hunting and destroying elements from the "threat". Most often, they do not deal well with the pulling back of the curtain revealing the bigger picture.
A few Agents understand a rough approximation of the truth:
Things came from the stars and fought over the earth billions of years before man, and now sleep in some infernal cycle of time. Man is the result of biological run-off; all earthly life is a fungus borne of alien shit, that has clung and crawled and evolved as these giants sleep. Soon they will wake, and remake the world. Leaving it as it once was, a lifeless globe.
As can be imagined, these Agents don't get too much sleep.
So, what do Agents know? It's easy to say Agents run a spectrum from first hand knowledge of an isolated supernatural incident, to seeing the grand sweep of pre-and-post human history. There are many shades of knowledge in Delta Green, and almost all of them are certain their point of view is correct.