At the beginning of the story Eliezer Wiesel is just a twelve-year-old boy who lives in a small and quiet town of Sighet in Transylvania with his family. He studies Jewish religion and mysticism preparing to enter the society of adults. Despite growing danger and worsening anti-Jewish laws, Eliezer’s family decides to stay at home. Even when the boy’s teacher suffers a near-death experience and tells him that Nazis are coming for their lives, nobody believes it.
In the spring the deportation starts. Nazis put the people in the cattle cars not allowing them to take anything with them, not giving them food and water. One of the women coming with them suddenly starts screaming about hell and fire pits they will be all thrown into. That way they are brought to Birkenau that was the sorting ground. Eliezer’s mother and little sisters are taken away and Eliezer and Schlomo can only hope they will be put to labor and not murdered in a gas chamber. Eliezer himself and his father Schlomo lie about their ages (one is too young and the other too old to stay alive) and they are sent to the labor camp. After seeing what happenes with the infants who are literally thrown to the fire pits of Hell - the incinerators, Eliezer rebels against God who allows this happen and from this time, he prays no more.
From now on Eliezer and Schlomo have to fight for their mere existence. Underfed and working almost to death they need to endure the creative and cruel punishments invented by guards. Frequent “checks” lead to decimations of the prisoners. Everyone who seems too weak to continue working or, on the contrary, strong-willed enough to stand for themselves, is sentenced to death. The Jews try to consolidate around their religion, traditions and culture to keep at least a spark of hope alive. There are rumors amongst the prisoners that the Jews are creating their own country in Israel, their Promised Land. They talk and dream about getting there after this horror ends, portraying it like an earthly Heaven.
At first, life in the concentration camp looks bad but not nightmarish. They are fed, and being loyal may save them from lots of troubles. The guards strip them of their possessions but the head of the block - also a Jew - tries to care about his people. He is soon replaced, thought, for being too soft and benevolent, and the next head of the block is much harsher.
Three weeks after the initial sorting they are transferred to Buna where they sort technical detail in the warehouse. The guards here are much more cruel. Eliezer sees one of them slowly strangling to death a child of his own age for being connected to the mythical “rebels” in Buna. Other prisoners are forced to watch. One of the guards threatens to beat Eliezer’s father until the boy gives him his gold tooth. Finally, Eliezer agrees and the local dentist pries the tooth out with a dirty spoon. Eliezer himself was beaten cruelly just for accidentally seeing the guard who had sex with a prisoner woman.
Eliezer falls deeper and deeper in despair. He is no longer touched by Jewish religion and culture, he doesn’t want anything except his and his father’s survival. The boy feels that he is losing his humanity and compassion but he is so exhausted he cares no more. He binds his legs and pretends they are healthy despite the terrible pain he feels, but his father isn’t so lucky. Once a doctor examines Schlomo and separates him from the other more able men. Schlomo begs him to pass another exam and he is given another chance. With great effort, the old man wins the right to live. Eliezer, in his turn, undergoes a surgery on his leg. He is supposed to feel better, but the boy isn’t given enough time to heal and the pain is getting worse.
As the USSR forces proceed, the prisoners are transferred once more. They have to walk through the snowstorms all the forty-two miles to Gleiwitz. People are still exhausted and underfed, they can’t go fast enough, freezing to death one by one. As jaded as Eliezer is, he still tries to care for his father and live for him. He sees that the son of one of the kindest people in the camp abandons his father and goes forward to relieve himself of that burden. But his father survives and during the break he wanders the camp, freezing by himself but still searching for his son or at least for his body. This sight touches Eliezer so deeply that he prays to God for the first time since they were parted from the rest of the family. The boy prays for strength that will allow him not to do what the priest’s son did.
When they reach Gleiwitz, there are only twelve of the people who Eliezer knows left. When they come to the barracks, everyone tries to get inside first. People suffocate in the crowd and step onto each other. Eliezer finds his Polish friend - a fiddler named Julek and tries to save him but fails. Julek worries not about himself but about his instrument. Now music is the sense of his life and he thinks of it like of his soul. Later, when Eliezer and his father are both safe, he hears Beethoven. It was the music Jews weren’t allowed to play in the camp. Eliezer thinks that it is the most beautiful and heartbreaking music he ever heard. Julek plays this last lullaby for dying and dead and later, long after the camp, Eliezer always remembers his face while hearing Beethoven.
Eliezer falls asleep. While he wakes up, he sees dead Julek, curled near him and his broken instrument beside him.
After the night the Nazi start another “sorting”. The ones who are considered weak are separated to be killed. Schlomo is in this group. Eliezer runs to him, shouting, so do other prisoners. The guards start to shoot, but in the resulting mess, Eliezer and others manage to save some of their relatives and take them to the “healthy” group.
They are pushed into the open cattle carts again. The people are so starved and thin that the Nazi manage to push a hundred in one cart. The prisoners can’t move or sit down. They are given one slice of bread per person and no water, but they are so thirsty that they try to eat snow from the heads and backs of their neighbors. This sight amuses the Nazi.
In the morning, the guards order to throw the corpses of those who froze to death at night away from the carts. Other prisoners are so ignorant that they are glad they will have now more place to sit and clothes to share. Shlomo is amongst the dead or so it seems. Eliezer shouts at him, slaps him and his father finally opens his eyes. The prisoners let him stay.
They proceed further, now without food, eating only snow to tame their hunger. Some people in the small towns they passed throw bread inside the carts and observe how people, driven mad by hunger, fight to death for it. Eliezer sees an old man who stole a piece of bread for his son, but his son is so mad he beats him to death and takes the bread - just to be beaten to death by other people too.
When they arrive to Buchenwald, there is a dozen people alive from the hundred who entered the cart. They are finally fed and bathed, but Schlomo is very ill. He asks Eliezer to leave him alone and let him die, but the boy refuses. He continues to care about his father, sharing food and coffee with him - and deeply ashamed, because deep inside he wants Schlomo to die and relieve him. Other prisoners try to convince Eliezer to take his father’s food and survive by himself, but he refuses until the very end. When his father is dying, he asks Eliezer to bring him water and the guard beats him for noise at night. Eliezer doesn’t stand for him afraid that he will be beaten too. That night Schlomo dies.
American forces are near the camp and Nazi decide to “evacuate” - e.g. murder - all the prisoners and then blow up the camp. The child block where is Eliezer is the last in queue, but when their turn comes they hear the sounds of shelling and shooting. All the children lie on the floor, most of them not caring about their fate. But the camp is liberated by Americans and the survivors are saved.
Eliezer is surprised that no one thinks about revenge or their families - only about food, sleep, good clothes and sex, like they forgot everything that happened and everyone who was killed by them or by Nazi. He himself wishes just to look in the mirror, but he sees only a corpse staring from the other side of it.