Primo Levi's account of his time as a prisoner of Auschwitz begins with his arrest as a Partisan in fascist Italy. After being interned in a detention camp, Levi is sent on a five day journey in a transport wagon to Auschwitz Birkenau, arriving in February 1944.

Levi is subjected to a degrading initiation into camp life at Monowitz, a subsidiary labour camp of Auschwitz. He enters the camp naked, his hair shorn. His camp identity number is tattooed onto his forearm. Levi realises he must learn the laws of the incomprehensible reality that he now inhabits. Numerous rules and regulations dictate his brutal day to day existence. Surviving on starvation rations, inmates face daily beatings whilst undertaking back-breaking labour. After a fortnight in the camp, Levi is consumed by an obsession with food and is unrecognisable to himself.

Part of a Kommando unloading supports from trains, Levi is injured and sent to the infirmary. It is here that the reality of the camp becomes clear to him: those deemed unfit to work are killed by poison gas, their bodies disposed of in the crematoria.

Despite suffering from perpetual hunger, exhaustion and cold, Levi finds some cause for hope: his friend Alberto who has maintained his integrity, unexpected moments of humanity, and the arrival of Spring.

Although illegal, trade on the camp's black market is rife and vital to survival. Prisoners barter anything of value for extra rations. Levi divides inmates into two categories: the Drowned and the Saved. The Saved are those able to find positions of authority, rising above the majority of inmates. The Drowned, weakened through hunger and exhaustion, become 'musselmen' and quickly die.

Levi applies to join a chemical work kommando, a privileged work squad for which he must sit a chemistry exam. In August, news of the allied advance reaches inmates. Rendered apathetic by the brutality of his existence, for Levi the world outside seems too remote to be of importance.

Levi meets Lorenzo, an Italian civilian worker who shows extraordinary kindness. Despite the risks involved – aiding inmates means imprisonment – Lorenzo gives Levi a daily ration of food and enables him to contact his family in Italy. He demonstrates that goodness can prevail.

Seventy percent of the prisoners will die over the winter months – October is a time of despair. A selection takes place, to sort healthy inmates from the sick. Levi must run naked past an SS man who will decide in a few seconds whether he will live or die. He survives the test, but is horrified by his arbitrary existence.

Levi is chosen to work in IG Farben's Buna Werke laboratory. He will work in the warmth through the winter and suffer neither cold nor hunger.

By December, the Russian army can be heard. Buna is descending into chaos following allied bombardments. Large numbers of prisoners from Eastern Europe are transferred to Auschwitz, bringing disease with them.

Levi and Alberto have adapted to camp life and are now adept at manipulating the system. The public hanging of an inmate, implicated in the demolition of one of the crematoria, forces Levi to confront the nature of his existence. Unlike the condemned man, who has shown strength through defiance, Levi feels he has been broken and is suffused with shame.

In January, Levi catches scarlet fever and is quarantined. He is thus not included in the main evacuation of the camp, as the Germans retreat from the encroaching Russian army. His illness spares him the fate of the majority of the twenty thousand evacuated from the camp; most of the prisoners, including his companion Alberto, perish on the march.

After surviving ten final days in the abandoned and deteriorating camp, Levi is liberated by the Soviet Army in January 1945.