On Friday, Rick Riordan, author of the Percy Jackson novels, broke his usual social media silence and decided to answer questions from fans on Twitter. The weekend-long Q&A session is now over, and we’ve got a summary of the answers for you right here.

Most of the time, Riordan doesn’t interact with fans via social networks. He’s too busy writing and it’s too much of a distraction for him. But the autumn equinox is a special time of the year for all demigods, and Riordan decided to open his doors and answer as many questions as he could.

He stayed spoiler free for The Mark of Athena and future books, but he did talk a little bit about some of our favorite characters and what he’s got planned for the future. He mentioned that Calypso, Coach Hedge, a few Titans, and Octavian will be back. Reyna has an important role in MoA, as well. Sally and Thalia, won’t be back for this book. Grover will be back later on in the series. Bianca and Luke are definitely gone.

Many people asked him about future projects, wondering if he’ll incorporate mythological stories from Japan, India, and even Arthurian legend. While he didn’t actually discount the possibility of doing some of them, he did say that it wasn’t likely right now. First he needs to finish the Heroes of Olympus series, then he’ll be working on his Norse series. After those are finished, he can start working on some other stories. He even has some non-mythological ideas floating around in his head that he may work on in the future.

He will begin work on his Norse series next year. He also didn’t count out the possibility of a cross-over novel where Percy and the Kanes meet up. In addition, he answered a question about the possibility of more Percy Jackson books after the Heroes of Olympus series is done, saying, “It’s WAY too early to talk about that! Dunno yet.”

While he didn’t answer the questions directly, he did tell us some things we can expect to learn in The Mark of Athena, like Jason’s birthday, the title of the fourth book, and what happened to the gray strands of hair of Percy and Annabeth. He also mentioned that the book has another good cliffhanger and there’s one scene that got him a little teary-eyed, mentioning that, “It’s just kind of a sweet, sad scene. Not a major tragedy or anything. I can’t get more specific.”

He answered a few questions not related to his books, as well. He mentioned that if he could choose which path of the gods he could follow, it’d probably be Set. He also shared his opinions on Doctor Who, The Hunger Games, Twilight, and Harry Potter. There are a few other fun answers thrown in there as well (like the fact that he prefers ice cream over chocolate).

Our favorite question and answer, however, had to be this one:

Who would’ve guessed that!?

Riordan answered about 130 questions over the course of the weekend, all of which you can read on his blog.

The Mark of Athena goes on sale on October 2.

Which question were you most excited to see answered?