What is gravity falls season 2 episode 15?

The 15th episode of season 2 of Gravity Falls is titled "The Last Mabelcorn." In this episode, Mabel makes a new friend, who happens to be a unicorn. Meanwhile, Dipper, Wendy, and Soos try to find a way to repair the Mystery Shack's damaged rift, which connects to other dimensions. As they search for answers, they run into an old enemy who threatens to destroy the town. The episode deals with themes of trust, loyalty, and the consequences of lying. It also features prominent appearances by several recurring characters, including Grunkle Stan, Ford, and Bill Cipher.