Watch Gravity Falls Season 3 Episode 3 Online. Best and Free Online streaming for Gravity Falls TV Show. We picked the best sites to stream s03e03. Simply pick a site below and click "Watch Now!" button next to it. Some of the links may be broken, please upvote the working and good links so other users see those links for Gravity Falls Season 3 Episode 3 s03e03 at the top of the list.