King Boo, who escaped his painting after the events of the first game, shatters the Dark Moon, a large crystalline object which has a pacifying effect on the ghosts that inhabit Evershade Valley, using the magical jewel embedded in his crown. This causes the ghosts to suddenly become hostile, forcing Professor E.Gadd to take shelter in a bunker while a dark, eerie fog covers the valley. E.Gadd immediately contacts Luigi and sends him to the bunker to get him to get the pieces of the dark moon.