Prologue: Welcome to Gravity Falls

What would happen if the Crystal Gems had settled down in a place other than Beach City, a little backwoods town just west of weird…? What if, upon coming to Gravity Falls for the summer, Dipper and Mabel were to befriend Steven and Connie? What kind of magical, mysterious adventures would they have? And, how would they fare against the combined threats of merciless Homeworld Gems and a certain triangular demon? Watch what happens when magic and mystery combine... in Universe Falls... (Steven Universe/Gravity Falls crossover AU)