When Thomas Hauser was selected for induction into the International Boxing Hall of Fame in 2019, his relationship with Muhammad Ali was widely cited. But Ali was just one of the many fighters who have shared momentous times with Hauser. For decades, elite fighters like Evander Holyfield, Manny Pacquiao, Roy Jones Jr., Bernard Hopkins, Ricky Hatton, Kelly Pavlik, Sergio Martínez, Jermain Taylor, Miguel Cotto, Gennady Golovkin, and Canelo Álvarez have welcomed him into their dressing rooms to record their journeys on fight night.

Gathering and updating more than thirty essays from Hauser's critically acclaimed yearly collections, In the Inner Sanctum celebrates these most dramatic hours in boxers' lives. In each account, Hauser chronicles the very moment when a fighter's physical well-being and financial future are on the line—when the fighter is most at risk and most alive.