On December 13, 1943, the twenty-four-year-old Primo Levi was arrested by the Fascist Militia and detained at a camp in Fossoli, near Modena. Nine weeks later, having admitted to being an "Italian citizen of Jewish race," he was sent to Auschwitz together with all of the other Jewish prisoners.
Everyone, he says: "even the children, even the old, even the ill."
In Auschwitz, one of Primo Levi's tasks, together with five others in his Kommando, was to scrape out the inside of an underground petrol tank. The work was exhausting, brutal and dangerous. The youngest of the group was an Alsatian student called Jean, a seventeen-year-old who was given the task of “Pikolo" or messenger-clerk in the mad bureaucracy of the camp.
During one of the assignments, Jean and Primo Levi are obliged to spend an hour together, and Jean asks Levi to teach him Italian. Levi agrees, and suddenly the Ulysses canto of the Commedia comes to his mind - how or why he does not know. As the two men walk towards the kitchens, Levi tries to explain to the Alsatian, in bad French, who Dante was and what the Commedia is, and how Ulysses and his friend Diomedes burn eternally in a double flame for deceiving the Trojans. Levi intones the admirable verses: 

The greater horn of the ancient flame
Began to shake itself, murmuring,
Just like a flame that struggles with the wind;
Then carrying to and fro the top
As if it were the tongue that spoke
Threw forth a voice, and said: "When ... " 

After that, nothing. Memory, which at the best of times betrays us,....