The first scenario that exposed me to Delta Green back when it was originally released and it hit all of the werid things that I really love about the setting. How it's grounded in the real world and that how one thing, upon discovery, can catostraphically ruin the lives of everyone in contact with it. There's a beautiful nihilism about The Last Equation that is wonderful to run and play. It's a great mystery that isn't about a monster and more about the horrors of the world that lie just beyond human comprehension. It's quintessentially Delta Green.