The winter before Dipper and Mable arrive in Gravity Falls, the town is swamped with a blizzard. At the Mystery Shack, employees Wendy and Soos are tasked with keeping the building in shape while their boss, Stan Pines, heads out to buy some supplies. But when a blackout hits, strange things start happening. Someone's watching the unsuspecting pair, and he seems to only want one thing: their deaths. #fanficfrightday