I knew that my father and his sister were in Auschwitz.

I also knew that you don't ask your father about the Holocaust.

Erno "Zvi" Spiegel was 2 years old when he was deported, along with 430,000 Hungarian Jews, to the Auschwitz-Birkenau death camp.

Mengele was going along and asked for "Zwillinge."

"Zwillinge" is German for "twins."

-I was 11 years old.

-Eleven.

[speaking Hebrew] And the first question was, "When can we see our mother?"

He said, "I'm sorry, but look at the flames over there."

Sometimes sibling who bore a striking resemblance to each other were mistakenly identified as twins.

INTERVIEWER: [speaking Hungarian] [speaking Hungarian] Erno Spiegel changed the boys' birthdates, making them twins and effectively saving their lives.

[speaking Hungarian] Children were spared from immediate death if they were twins: alive but destined to become subjects in the macabre experiments of the camp's chief doctor, Josef Mengele.

I started crying... for a little while, and then never again.

Though he was in charge of the twins, Spiegel was also a subject of Mengele's experiments.

Through it all, he remained focuse on the well-being of the boys.

He started teaching us a little bit of maths here, a little bit of geography.

He was a father figure to us.

I saw the first Russian soldier passing by under the window.

And that's it.

That's liberation.

Zvi Spiegel had the idea of assembling the kids and taking them home.

They faced the prospect of a long and dangerous journey back to their homes, uncertain if those homes even still existed.

We went on trucks, trains, walked.

In the bitter cold.

It took us nearly two months.

Not many people can say that they owe their life to some stranger.

It is a story that the hero is my father.

But the questions that we should ask ourselves... Who are we?

And what would we choose to do?