Popular author John Green's next novel, 'Turtles All the Way Down', will be out in October

LOS ANGELES: Best-selling author John Green has announced that he will publish a new novel this October.

Releasing on October 10, " Turtles All the Way Down" is the story of 16-year-old Aza Holmes, a young woman who grapples with mental illness while investigating the disappearance of a fugitive billionaire, reported Entertainment Weekly.

"I've been working on 'Turtles All the Way Down' for years, and I'm so excited to share it with readers this October. 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," Green said in a statement.

"Turtles All the Way Down" comes nearly six years after the release of Green's last book and international phenomenon "The Fault in Our Stars" in 2012.

His novels have also been adapted for the big screen: 2014's "The Fault in Our Stars" with Ansel Elgort and Shailene Woodley and 2015's "Paper Towns" with Nat Woolf and Cara Delevingne.