Even 8 years after Gravity Falls ended, I still have questions about the show's many mysteries and characters, which is what makes The Book of Bill so exciting.

The upcoming limited edition has a glow-in-the-dark slipcase and comes with several collectibles featuring Gravity Falls ...

Alex Hirsch talks about Bill Cipher, Summerween, Gravity Falls, and which character deserves a 50 Shades of Gray-style spinoff. The Book of Bill is out now.