EXCLUSIVE: @johngreen is releasing his first new book in almost six years: Turtles All The Way Down! https://t.co/jGJ0mfxdGD pic.twitter.com/Ij5EH0XbUu

— Good Morning America (@GMA) August 10, 2017

Fans have been waiting five years now for John Green’s much-anticipated follow-up to his last novel, the international phenomenon The Fault In Our Stars. Green has clarified that this new book will be titled Turtles All the Way Down, and is due out in October. On Thursday, the official cover was also revealed on Good Morning America.

The cover for Green’s new book features an orange swirl against a white background, which seems like another nod to the anecdote referenced in the title. The story, which begins Stephen Hawking’s book A Brief History of Time, goes that a scientist was once giving a lecture on astronomy when a pushy audience member told him he was wrong. The world did not revolve around the sun, she said — as a matter of fact, it rested on the back of a turtle. When the scientist tried to collapse her argument by asking what the turtle was standing on, the woman laughed and said, “It’s turtles all the way down.”

The anecdote is a humorous illustration of both people’s obstinacy in the face of facts and the problem of infinite regression when trying to think philosophically about the nature of the universe. That seems to share some parallels with the plot of Green’s book. According to publisher Dutton Books for Young Readers, Turtles All the Way Down focuses on 16-year-old Aza Holmes, who is “navigating daily existence within the ever-tightening spiral of her own thoughts.” As she deals with mental illness, Aza sets out to look for a missing billionaire in a story about “lifelong friendship, the intimacy of an unexpected reunion, Star Wars fan fiction, and tuatara.”

Watch the Good Morning America video below. Turtles All the Way Down is due out Oct. 22.