The Pulitzer Prize-winning Woodward will publish a book about the Trump administration called Fear: Trump in the White House. The book, which will be released on Sept. 11, will include interviews that spanned hundreds of hours with sources inside the White House, according to the book’s publisher Simon & Schuster. Woodward was also able to obtain meeting notes, files, and personal diaries from inside the White House.

Woodward is one of the most prominent investigative journalists in the world. He’s best known for his work in the Watergate scandal that took down the Nixon administration. He’s also profiled and investigated several other presidents during his career.

Now, he’s turning his attention to a Trump administration that has been inundated with infighting and turnover. Reports from inside the White House suggest the staff can at times be frustrated by the president, his tweeting, and for saying things that later need to be clarified.

Still, he’s also surrounded himself with loyal supporters, including his son-in-law Jared Kushner and daughter Ivanka Trump. Exactly who will be cited in the Woodward book is unknown.

Fear is likely to be a strong seller. All of Woodward’s previous 18 books have been a national bestseller.