Stan has to reveal his past to Dipper and Mabel, along with the secrets of his twin brother, Stanford “Ford” Pines. Stan’s real name is actually Stanley Pines: thirty years ago Ford constructed the portal but was trapped inside it due to a mishap with Stanley, his estranged con-artist brother. Stanley assumed his brother’s identify as “Stanford Pines”, and spent the next thirty years trying to fix the portal to get Ford back. He was finally able to reactivate the portal after the kids discovered Ford’s missing journals. In the end, the agents leave after having their memories erased, and Stanford decides to live in the underground lab under the Mystery Shack. Grunkle Stan makes him promise he will leave the kids alone after being told that he would have to leave the Mystery Shack at the end of the summer.
