The Tattooist of Auschwitz

It is a Fiction, but is based on a real story:

This novel is based on the true story of Lale and Gita Sokolov, two Slovakian Jews, who survived Auschwitz and eventually made their home in Australia. In that terrible place, Lale was given the job of tattooing the prisoners marked for survival - literally scratching numbers into his fellow victims' arms in indelible ink to create what would become one of the most potent symbols of the Holocaust. Lale used the infinitesimal freedom of movement that this position awarded him to exchange jewels and money taken from murdered Jews for food to keep others alive. If he had been caught, he would have been killed; many owed him their survival.