Who is Twins' Father, Zvi Spiegel from Children of the Flames: Dr. Josef Mengele and the Untold Story of the Twins of Auschwitz and what is their importance?

Zvi Spiegel arrived at Auschwitz in his twenties. When Mengele discovered he was a twin, he appointed Spiegel as a guardian to the twins in the boys' barracks. Spiegel went out of his way to protect the children, often delaying or outright lying to them about the fates of their parents or siblings. Whenever a new boy was brought to Spiegel, he made the promise that one day he would make sure they got home. When a new doctor ordered the executions of the boys in his unit, Spiegel went to directly to Mengele and convinced him to stop the execution.

After the war, Spiegel the promise he made to get all the boys home. He took a group of the surviving male twins and walked them across country toward his own hometown. Spiegel was eventually able to return many of the boys home by train. In return, the boys sent him letters telling of their fates. When Spiegel returned to his own home, he found a family living in his house. As a result, he left town, started over, got married, and took a job as an accountant. Many years later, Spiegel reunited with a large number of the young boys he cared for.