Book excerpt: From #1 bestselling author Brad Meltzer, a riveting collection of the 10 greatest historical conspiracies of all time, from around the world and across the eras, including Hitler's interest in capturing the Roman "Spear of Destiny" to the Kennedy assassination (did Oswald act alone?) to Area 51. Previously collected in the interactive book History Decoded, these stories are now collected in a reading book for any history buff.