Brad Meltzer enlists America's help to find lost and stolen historical artifacts missing from museums and public collections. One of the most shocking missing items is the iconic Ground Zero Flag, raised by firefighters on 9/11. A few hours after it was raised, this sacred relic simply disappeared. Next, a multi-million dollar collection of jewel-encrusted swords and daggers that once belonged to Harry Truman is stolen in a daring daylight heist. Then, the incredible story of John Dillinger's Tommy gun stolen from a police station and missing for decades.