My name is Dipper Pines. When my sister and I were five, we saw our parents murdered by something impossible. Then an accident made us the impossible. To the outside world we're just teenagers, but secretly we solve mysteries and find other metahumans like us. And one day, we'll find who killed our parents and finally get justice for their deaths. We are the Mystery Twins! Flash AU

Mason "Dipper" and Mabel Pines get transported into an alternative world at the end of Season 2. A world without Gravity Falls as a town or a cartoon. They're stuck there too. No way out, no way back in. Can they survive in their new surroundings without supernatural, without friends, and with a new family?

Dipper and Mabel Pines had always been and will always be different. Dipper was abnormally smart and Mabel was abnormally fun and they both were the children of an all-powerful dream demon named Bill Cipher.