One of the most celebrated, beloved entertainers of the wartime era takes off from England in heavy fog, heading to France to entertain troops. His plane vanishes. Glenn Miller's disappearance is perhaps the biggest mystery and cold case of World War II. This HISTORY DETECTIVES investigation contains a great deal of new information: Miller's pilot was a rank novice who had never flown over the English Channel, never mind in appalling weather; documents from a Lancaster bomber pilot support another possible accounting of the plane's disappearance; and a 17-year old plane spotter's notebook - discovered in 2012 at a UK Antiques Roadshow - answers a question that has long baffled investigators: which route did Miller's aircraft take? In addition, the German-speaking Miller was working for the U.S. Army's Psychological Warfare Division, recording German language propaganda broadcasts and musical performances.