Command D was an underground bunker in upstate New York created by Project Cadmus. While the facility was run by King Faraday, to him, it was a post apocalyptic emergency scenario bunker and thus, whenever somebody entered, they were not allowed to leave. As such, he kept the bunker hidden below a farmhouse. Only when Brother Eye helped defeat the Brainiac God in Futures End did Faraday enter the bunker, bringing Ethan Boyer with him.