“Were you on the train?”

Hedy Mayer, Devora Spira, Peska Friedman and Berta Rubinsztejn felt no need to ask: which train? Only one train was on everyone’s lips on Tuesday night at a Manhattan gathering of Hungarian Jews who had escaped the Holocaust. There had been many trains to Auschwitz. There had been only one train to life, and the four women, now all in their 80s, had been on it, along with about 1,680 others.

It was a train from Budapest that stopped for several months at the Bergen-Belsen concentration camp and finally made its way to Switzerland and salvation. The trip was arranged in 1944 during the darkest days of the Nazi genocide by Rezso Kasztner, also known as Rudolf or Israel Kastner, a Jew who was to rescue more Jews than Oskar Schindler.

He had done this by negotiating face to face with Adolf Eichmann, the administrator of Hitler’s Final Solution, and paying $1,000 a head while concealing, enemies later said, the full measure of the peril that was to claim an estimated 550,000 of Hungary’s 825,000 Jews, and vouching at the Nuremberg trials for an SS colonel, Kurt Becher. For this, Mr. Kasztner was shot to death in 1957 at age 51 in Tel Aviv.

Image Among the exhibits: drawings by a survivor and a list of riders whose freedom Rezso Kasztner purchased. Credit... Suzanne DeChillo/The New York Times

For years his name was anathema. Reviled as a Nazi collaborator whom an Israeli judge said had “sold his soul to the devil,” Mr. Kasztner, a journalist and official in Israel’s ruling leftist workers party, Mapai, was denounced in court, demonized in print and spat upon on the street. Rage against him brought down the Israeli government in 1955 and all but ignited a civil war. His three right-wing killers were pardoned seven years into their life sentences. Israel’s Supreme Court later cleared him of all charges, but the stigma stuck. His name graced no memorial walls, even at Yad Vashem, Israel’s shrine to victims of the Shoah, although in 2007 it accepted some of his papers.