A thoughtful companion volume to the earlier <i>Surely You Are Joking Mr. Feynman!</i>. Perhaps the most intriguing parts of the book are the behind-the-scenes descriptions of science and policy colliding in the presidential commission to determine the cause of the Challenger space shuttle explosion; and the scientific sleuthing behind his famously elegant O-ring-in-ice-water demonstration. Not as rollicking as his other memoirs, but in some ways more profound.