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. The most shocking missing item of all: the iconic Ground Zero Flag, raised by firefighters on 9/11. A few hours after it was raised, this sacred relic simply disappeared. Then, a multi-million dollar collection of jewel-encrusted swords and daggers that once belonged to Harry Truman is stolen, in a daring daylight heist. Plus: the incredible story of John Dillinger's Tommy gun, stolen from a police station before becoming his favorite weapon, goes missing for decades.