What They Didn't Burn

By Mel Laytner.  They burned millions of bodies and tried to destroy all the records.  But German efficiency in bureaucratic record keeping produced such a swarm of records that the author used the surviving documents to verify the stories his father, a Holocaust survivor, told him as a child.  I am only four chapters in, but for a guy who lives for primary sources this is just top fascinating to put down.  

His father was caught at one point arranging to have IDs forged with the help of some British POWs who worked in the same coal to oil refinery.  This should have led to execution but he apparently knew where some diamonds could be found and the SS did not want to kill the goose that laid diamond eggs.