Holy crap, we're getting a new John Green book this year and the title is perfect

More than five and a half years after his bestselling The Fault in Our Stars, John Green's next novel is coming this fall, his publisher announced Thursday.

According to a press release from Penguin, Green's sixth novel tells the story of 16-year-old Aza Holmes who is "looking for clues in the disappearance of a fugitive billionaire, while grappling with mental illness." It's also about New Zealand reptiles, so that's fun.

“I've been working on Turtles All the Way Down for years, and I’m so excited to share it with readers this October,” Green said in a press release from Penguin Random House. “This is my first attempt to write directly about the kind of mental illness that has affected my life since childhood, so while the story is fictional, it is also quite personal."

That quirky title is no random combination of words; It's an expression referring to the "unmoved mover" paradox, an idea that the Earth is flat and floating on the back of a giant turtle on top of a tall column of turtles.

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Green has spoken at length about his writing process and the struggle to followup TFiOS, as in the above vlogbrothers video. The Fault in Our Stars sold over 23 million copies worldwide and was adapted into an MTV Movie award-winning film in 2014 starring Shailene Woodley and Ansel Elgort.

Like Green's other books, Turtles All the Way Down will be published by Dutton, an imprint of Penguin, and will be edited by his longtime colleague Julie Strauss-Gabel, President and Publisher of Dutton Books for Young Readers.

“As with all of John’s work, Turtles All the Way Down is both a singularly personal read and a catalyst for conversation and community," Strauss-Gabel said in the press release. "It is with tremendous pride and great excitement that his longtime Penguin family can finally shout this news to the world.”

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Green announced the news officially at VidCon, currently taking place in Anaheim, where he will spend the weekend with fellow YouTubers and fans.

"In the last two years I have been able to work consistently on a story, and it's been really great," Green told the audience at the VidCon mainstage. "It’s been really fun -- hard, but fun...and I kept it a secret from you guys because I really wanted this moment I really wanted to be able to tell you in person."

Green will sign 200,000 copies of the initial print run (he signed the entire TFiOS first order, which was 150,000 books). Turtles All the Way Down is available for preorder now.