It has been nearly five and a half years since author John Green released his best-selling novel, The Fault in our Stars. Now, fans of the author can get excited because he announced at VidCon that he is releasing a new book.

During the opening of VidCon 2017, John along with his brother Hank (Who make up the Vlogbrothers on YouTube) gave various announcements, but the one that left fans speechless and joyful was that John Green has written another book, entitled Turtles All The Way Down.

What we know about Turtles All The Way Down

The story is about 16-year-old Aza Holmes, a young women who struggles with mental illness and ventures off to solve a mystery of a missing billionaire. Dutton Books describes the book as being “about lifelong friendship, the intimacy of an unexpected reunion, Star Wars fan fiction, and tuatara. But at its heart is Aza Holmes, a young woman navigating daily existence within the ever-tightening spiral of her own thoughts.”

“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 statement. “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.”

John even took to Twitter to let fans know of the release date:

Turtles All the Way Down. October 10th 2017.

— John Green (@johngreen) June 22, 2017

John Green has written many books, including 2005’s Looking For Alaska, 2006’s An Abundance of Katherines, 2008’s Paper Towns and 2009’s The Fault in Our Stars, to name a few. In 2007, John, along with his brother Hank, formed and started the VlogBrothers channel on YouTube. Since then, John and Hank have launched events such as Project for Awesome and VidCon. John also oversaw production when his books The Fault in Our Stars and Paper Towns were turned into motion pictures.