Six Terrifying Scenarios 

"The sciences, each straining in its own direction, have hitherto harmed us little; but some day the piecing together of dissociated knowledge will open up such terrifying vistas of reality, and of our frightful position therein, that we shall either go mad from the revelation or flee from the deadly light into the peace and safety of a new dark age." —H.P. Lovecraft, "The Call of Cthulhu"

A Night at the Opera collects six Delta Green operations that were previously published only in PDF or in standalone paperback modules. Combined, they expose a team of Agents to the edges of the horrors of the world of Delta Green, then suck them into abysses of fear and desperation from which the world itself may never emerge.

• REVERBERATIONS: An introductory scenario in which the Agents confront foes that were old before Delta Green was born. By Shane Ivey.
• VISCID: Investigating a geneticist's gruesome death, the Agents confront lethal conspiracies and horrors that never should have been made. By Dennis Detwiller. (Available on its own in late December 2017.)
• MUSIC FROM A DARKENED ROOM: The Agents must investigate a house that may be haunted by things more terrifying than ghosts. By Dennis Detwiller.
• EXTREMOPHILIA: Can the agents stop the spread of a terrifying threat? Or will they become just another vector for the disease? By Shane Ivey.
• THE STAR CHAMBER: The Agents must hear and adjudicate a horrific after-action report from another team—by way of playing out scenes from the earlier mission in between scenes of the present day. By Greg Stolze.
• OBSERVER EFFECT: The Agents investigate a cutting-edge physics laboratory that may have looked a little too deeply into the nature of reality. By Shane Ivey.

An index helps Handlers build broader connections between horrors in their campaigns.