"Auschwitz is unique," explains series producer and writer Lawrence Rees. "It has a physical beginning in May 1940 and physical ending in January 1945, and is the site of the single largest mass murder in the history of humanity." Like the series, this website uses Auschwitz as a prism to try and understand something of the extermination process and of the mentality of the people who committed the crime. Rational, sane people sat down in various stages and made key decisions that ended in the killing of over six million women, men and children.