The announcement of a new book that offers a “behind-the-scenes” glimpse into the Jan. 6, 2021, committee’s investigation, penned by a former adviser to the committee, has rocked insiders, The Washington Post reports. Lawmakers and committee members were “largely unaware” of the book’s existence, the Post reports, until a tweet promoting an upcoming 60 Minutes appearance by former Rep. Denver Riggleman (R-VA). The book, titled The Breach, will hit shelves on Tuesday, one day before the Jan. 6 panel holds its final public hearing. Riggleman spent eight months working alongside the committee before his resignation in April and claims it was his team that analyzed phone records and texts of those involved in the attack on the U.S. Capitol. Notably, when Donald Trump’s former White House chief of staff Mark Meadows supplied the committee with more than 2,300 texts, 60 Minutes said it was Riggleman and his team’s job to “put names to numbers.” In its promotion of the book, publisher Pan Macmillan says the book “includes previously unpublished texts from key political leaders” and “contains shocking details about the Trump White House’s links to militant extremist groups.”