<Tr> <Td> ← Previous "Land Before Swine" </Td> <Td> Next → "Gideon Rises" </Td> </Tr> <Tr> <Td_colspan="2"> List of Gravity Falls episodes </Td> </Tr> <P> "Dreamscaperers" is the nineteenth episode of the first season in the animated series Gravity Falls . The episode is the first of the two - part season finale, the second being "Gideon Rises". It was first broadcast on July 12, 2013, on the Disney Channel . It was written by series creator Alex Hirsch, alongside Matt Chapman and Tim McKeon, and directed by Joe Pitt and John Aoshima . It marks the first appearance of Bill Cipher . </P> <P> The series follows twins Dipper and Mabel, who live with their grand uncle, Grunkle Stan in a tourist trap called the Mystery Shack in the fictional town of Gravity Falls, Oregon . In this episode, Stan's nemesis Gideon (Thurop Van Orman) tries burglary into the Mystery Shack to steal the deed of the property from the safe . However, he is stopped by Grunkle Stan and thrown out . Gideon then summons a demon called Bill Cipher (Hirsch) to help him . He is also known as Triangle Triangle, Line, Line, Circle, etc...Gideon asks Bill to invade Stan's mind and steal the combination to the safe, which is vincindoria . Dipper Pines (Jason Ritter) with his sister Mabel (Kristen Schaal) and friend Soos also go into Stan's mind to stop Bill from finding out the combination . </P>

When does bill show up in gravity falls