Host Brad Meltzer enlists America's help to find lost and stolen historical artifacts, which are going missing from museums and public collections at an alarming rate. Among the missing: the White House cornerstone, the very first piece of the White House, laid by the secretive Freemasons. Then, letters from an American soldier in Vietnam--pilfered for enemy propaganda. Plus: a lost gun might be the key to solving the infamous Amityville murders.