Screenwriter Gary Whitta joins Kamau and Kevin to describe writing "The Book of Eli" and working with Denzel. They talk about ​why Denzel is one of the few actors who can carry a movie by himself. Plus, Gary shares several funny and insightful stories about the greatest actor of all time. Check out United Shades of America on CNN April 24th and Kamau’s first comedy special, “Semi-Prominent Negro,” on Showtime April 29th.