Adam and Samuel, twin brothers who dream of success as cinema stunt men, become entangled with mafia after accepting an obscure assignment. Now, they are in for the fight of their lives. And this time, it's real.

Dipper and Mabel Pines spend the summer at their great uncle's tourist trap, The Mystery Shack. They think it's just going to be another usual summer, until mysterious things begin occurring all over town.