Joshua Bolten was deputy chief of staff for policy under President George W. Bush, but was acting chief of staff in the White House on September 11, 2001, as Andrew Card was traveling that day with the president. Bolten recalls the high-level conversations that took place in the bunker beneath the White House as it became clear that multiple airplanes had been hijacked as part of the 9/11 terrorist attacks. He describes how Vice President Dick Cheney confirmed the military order to intercept United Airlines Flight 93 as it was being flown toward the nation’s capital.