From the back cover:
YOU ARE THE APOCALYPSE
Born of the U.S. government’s 1928 raid on the degenerate coastal town of Innsmouth, Massachusetts, the covert agency known as Delta Green opposes the forces of darkness with honor but without glory. Delta Green agents fight to save humanity from unnatural horrors—often at a shattering personal cost.
In DELTA GREEN: THE ROLE-PLAYING GAME, the players are those agents. They fight to keep terrors from beyond space and time from infecting the world and claiming human lives and sanity. The Handler is the game moderator who creates and interprets their world, presents the unnatural horror that they investigate, and describes the awful aftermath of their sacrifices.
The HANDLER'S GUIDE is a game-moderator-only rulebook for DELTA GREEN: THE ROLE-PLAYING GAME. It includes:
A history of the world of Delta Green from prehuman history to the present day, with campaign tips and scenario seeds on every page.
Horrifying rituals, unnatural entities, and reality-shattering Great Old Ones.
Rules for creating new threats to shock and terrify your agents.
The secretive Delta Green organization in deep and disturbing detail—and the other ruthless conspiracy that claims it is the real Delta Green.
Guidelines for creating original scenarios and campaigns using the resources in this book.
“Operation FULMINATE: The Sentinels of Twilight,” a sample scenario, ready to play.