*Oprah Winfrey chose Colson Whitehead‘s “The Underground Railroad” as the next title for Oprah’s Book Club. The title was originally set for release Sept. 13, but the publisher moved its release date up more than a month to coincide with the announcement.

The novel is available now, and with Oprah’s endorsement, the title is guaranteed to be one of the biggest books of the year. The premise of his new novel imagines: What if the Underground Railroad were an actual railroad?

“Most people think it’s a figure of speech,” a slave catcher says, in this version of the antebellum South. “The black mouths of the gigantic tunnel opened at either end. It must have been twenty feet tall, walls lined with dark and light colored stones in an alternating pattern. The sheer industry that had made such a project possible. . . . The steel ran south and north presumably, springing from some inconceivable source and shooting toward a miraculous terminus.”

Writing on Twitter, Oprah warned one reader, “sometimes you’ll have to put the book down. No kidding. It gets rough!”

The publisher, Doubleday, secretly started shipping out 200,000 copies in anticipation of Oprah’s announcement. When Whitehead got the call about the Oprah news, he said in a press release:

“I let out a stream of loud, joyful expletives—which was awkward because my plane had just landed and everyone looked at me like I was crazy … Oprah has introduced so many wonderful books to people, from The Song of Solomon to The Sound and The Fury, that I’m honored and grateful that The Underground Railroad is joining such great company. You write the best book you can, and hope it finds its way. This is the best kind of sendoff.”

READ RELATED STORY: Oprah Winfrey to Star in Ava DuVernay’s ‘A Wrinkle In Time’

Time magazine notes that Whitehead is a MacArthur genius and the author of “The Intuitionist,” “Sag Harbor” and other books.

Watch Oprah’s endorsement below and take her advice to “get it, then get another copy for somebody you know, because you are definitely gonna want to talk about this with somebody once you read that last heart-stopping page.”