Primo Levi was imprisoned in Auschwitz in February 1944 to January 1945. During his time there, he was assigned several work details, and eventually he was one of three men placed on the chemical kommando. Because he was in the infirmary in January 1945, he was not evacuated from Auschwitz with the tens of thousands of other prisoners. This resulted in his being freed 10 days later when the Russian army arrived.
Alberto arrives at Auschwitz with Levi. He is atypical in that he does not let his imprisonment "corrupt" him. He maintains optimism and is a friend to Levi during the time, almost a year, that they are held at Auschwitz. He stops at the infirmary to say goodbye to Levi when the camp is evacuated.
With Arthur and Levi, Charles searches for food and other supplies. He is the person who consistently joins Levi in search of provisions. When one of the patients falls during the night trying to get to the latrine, he is the one who cleans and helps him. He survives and becomes a teacher again. Afterward, he and Levi stay in touch via letters.
Lorenzo gives Levi bread and a warm vest, and sends a postcard to Italy for him. He asks for nothing in return. He is, according to Levi, why Levi survives—because of his show of humanity.
Steinlauf is unlike most prisoners in that he bathes, despite camp conditions. He explains to Levi that this is resistance to the camp's objective of reducing them to animals. It means he is resisting, even in this small way. He says they have the "power to refuse our consent."