KG 200 was a secret, specialized branch of the German Luftwaffe formed before World War 2 for espionage and recognizance. Though most of the documents detailing their most secret missions were destroyed before allied powers could seize them, some did survive.
One of these missions, code named Apocalypse, was the first known attempt at advanced biological warfare on humans. The records of Apocalypse are incomplete, but the evidence confirms the horrific effects that Apocalypse had on one small farming village in Poland.
Only now, decades later, is that evidence being released to the public.