In Jodi Picoult's novel The Storyteller, baker Sage Singer works alone on the night shift at a small bakery and avoids people during the day, in both situations concealing from other people both a facial scar and the guilt she feels about the accident that caused it. When she forms an unlikely friendship with 95-year-old Josef Weber, she expects that all she will learn is to play chess with him, so it is a shock when he reveals that he was a guard at a Nazi concentration camp, and later that he wants her to help him die. Both the confession and the request turn Sage's world upside down, but eventually give her new insights into herself, her family, and the nature and purpose of forgiveness.

Twenty-five year old Sage Singer works at Our Daily Bread bakery in her small New Hampshire hometown. She welcomes the opportunity to work alone overnight because it helps her hide from the rest of the world, a habit she has formed since a car accident three years previously left her face scarred and her mother dead. Her relationship with a married undertaker (Adam) is a source of friction with her boss/best friend, Mary, but Sage does not feel she deserves any better.

Sage's life changes when she meets and becomes friends with ninety-five year old Josef Weber, a former German teacher and baseball coach beloved by the community. His reputation, however, is the main reason she is shocked when he confesses that he was an officer in Hitler's army and took part in the mass murders of Jews and other undesirables. He further surprises the Jewish Sage by first asking her to forgive him and then asking her to help him die. Sage immediately contacts the police, who put her in touch with Leo Stein, a thirty-seven year-old divorced attorney with the Department of Justice and passionate hunter of former Nazis. He is skeptical of her claim at first, but after further conversation becomes intrigued enough to ask her to prompt Josef for more information, and eventually to come to New Hampshire to investigate the case himself.

When Leo says that, if possible, they need an eyewitness who can identify Josef (who now says his name is actually Reiner Hartmann), Sage approaches her grandmother Minka, a native of Poland who was imprisoned in a concentration camp during the war. After some initial doubts, Minka agrees to tell her story to Sage and Leo. She describes an idyllic childhood in Poland that gradually disintegrated into horror as the Nazis moved all the Jews into ghettos and eventually to concentration camps. After all other members of Minka's family were murdered, she ended up in Auschwitz, where her knowledge of German gained her a job in the office of Franz Hartmann, an administrator at the camp and not nearly as innately cruel as his brother Reiner. Minka also tells Sage and Leo that in an effort to keep herself and other inmates sane, she wrote a lengthy story involving a young woman, two very different brothers, and a number of mythical creatures, using the only paper she has -- the backs of photos she takes from the belongings of dead prisoners. When Franz reads the story he becomes fascinated with it, seeing it as an allegory representing his brother and himself. He subtly gives Minka extra food and warm clothing on the condition that she write an additional ten pages each night and read them to him the following day. Their relatively peaceful relationship is challenged, however, when Reiner kills Minka's best friend in cold blood and Franz saves her (Minka's) life by beating her savagely and sending her away before Reiner can kill her too.

The description of the murder of Minka's friend is the evidence Leo needs to pursue a case against Josef, but first he must get Sage, with whom he has fallen in love, to obtain a recorded confession, which she does. Then, while Leo is preparing his case, Sage bakes a poisonous plant into a roll and gives it to Josef, fulfilling his request that she kill him. The next day, Sage goes to Josef's house with Leo, who is not surprised to find that such an elderly man has died. Sage is shocked, however, when she secretly learns that Josef was not Reiner Hartmann after all. Putting a few facts together, she realizes that Josef was actually Franz Hartmann and that he still retained Minka's story written on the backs of photos.