When Dipper starts being haunted by nightmares, he knows there's only one being who could possibly be behind them. Takes place at some point in Season 2 after Sock Opera. (This story does contain a relationship between Bill and Dipper. Just so you know.) Rated T just in case.
Gravity Falls - Rated: T - English - Romance/Supernatural - Chapters: 10 - Words: 19,470 - Reviews: 42 - Favs: 74 - Follows: 59 - Updated: 1/23/2015 - Published: 12/5/2014 - Dipper P., Mabel P., Bill