The Pines Family resolves to get back to normal by throwing a "Mystery Shack is Back" party ... but nothing is normal in Gravity Falls!

Cast: Kristen Schaal, Jason Ritter, Alex Hirsch, Linda Cardellini, Nick Offerman, Brad Abrell, Jennifer Coolidge, Jessica DiCicco, John DiMaggio, Carl Faruolo, Keith Ferguson, Will Forte, Kevin Michael Richardson, Michael Rianda, Gregg Turkington