Some 50 former inmates of the largest of the Nazi death camps at Auschwitz-Birkenau have made the trip to Poland for the 80th anniversary of the camp's liberation. How to process the collective folly of the industrial-scale mass extermination of 1 million Jews, along with 100,000 others, in the space of a few short years? The Holocaust shattered the belief that technology could only be synonymous with progress and on that score, the gas chambers serve as a cautionary tale.

How do citizens and nations remember the Holocaust in 2025? From the former Soviets whose forefathers liberated the camps, to nations at the other end of the globe untouched by World War II, what's the lesson?

The words "never again" ring hollow in today's world. An all-too-long list of genocides have unfolded since. How, then, to talk about it?

Produced by François Picard, Théophile Vareille, Elisa Amiri, Ilayda Habip.