A look back to 2019, and a show about people vanishing in groups. What happened to the 9th Roman Legion. They marched north to deal with the Picts, and were never seen again. How about the 5th Battalion Norfolk, who charged into a wooded area near Kavak Tepe, and vanished. 3,000 heavily armed Chinese soldiers disappeared in 1937 while holding the west end of the Marco Polo Bridge. Their equipment was there, but no soldiers to use it.