... for when you gaze long into the abyss. The abyss gazes also into you.
First Things Last
An introductory scenario for Delta Green
You've seen things, been entangled in a situation that you can't readily explain, gone beyond that which science and rationality can quantify. You do know that it wasn't good, and didn't make it out unscathed.
Afterwards, you have come into contact with what you initially assumed was the government. Maybe they bailed you out of a tight spot, or maybe they came around to pick up the pieces, even before you called 9-1-1. They asked a lot of questions, and answered very few.
They told you to keep your mouths shut about your unnatural experiences, go back to your day jobs, and you did. You were taught contact protocols, code words, memorized numbers and addresses. Sometimes you were contacted, to run a package from A to B without opening it, run a check on a name, buy and program some untraceable cell phones. You did so, and let your handlers know that you wanted to know more, wanted to do more.
You just got the notice. "Night at the Opera", code for grab your go bag, lie to your family, and meet at a Post Office in upstate New York, a few hours drive.
Welcome to Delta Green.