In 'Letterman: The Last Giant of Late Night,' Jason Zinoman meticulously presents the life and legacy of David Letterman, one of television's most influential talk show hosts. The book reveals the metamorphosis of Letterman's comedic style across three distinct periods, showcasing how his ironic wit and reclusive nature impacted modern comedy and shaped a generation. Zinoman examines Letterman’s early beginnings, his dynamic with writers, especially co-creator Merrill Markoe, and the behind-the-scenes of his iconic segments. This biography is a tribute to Letterman's indelible mark on pop culture and a deep dive into the comedian's complex persona, both on and off the screen.