Mystery Shack: tourist trap with a hidden history.
Plot: Twins, Dipper and Mabel Pines, spend the summer with eccentric great-uncle Stan in a strange town in Oregon. They discover a journal that reveals mysteries, encountering supernatural creatures. An evil triangle demon Bill Cipher, one big eye, dark humor.
Weirdmageddon: apocalyptic event that occurs when Bill Cipher and allies, invade. Needs enter Mystery Shack as it has a portal he needs. Bill can drink/eat from his eye. 