The Reader takes place in post-war Germany, between the late 1950s and the mid 1990s.  Narrated by protagonist Michael Berg, it is an account of the long term psychological and emotional effects of a relationship he had as a very young man.

One October afternoon, when he is fifteen, Michael is sick in the street on his way home from school.  A stranger comes to his aid, cleaning him up and comforting him when he becomes distressed.  He goes back to thank her the following spring, once he has recovered from hepatitis.  She is surprised to see him again, but allows him to wait while she changes out of her work clothes.  Michael watches her undress through the open door, then runs away when she notices.  He returns a week later; this time they become lovers.  Her name is Hanna.  She asks Michael to read to her after noticing his school books, and this becomes an important part of their routine.  The affair continues until the beginning of August, when she suddenly disappears.  Michael is heartbroken.

He unexpectedly sees Hanna some years later; as a law student attending a war crimes trial, he is shocked to discover she is one of the defendants.  He learns that, as an SS guard, she allowed a group of female Jewish prisoners to burn to death in a locked church during an Allied bombing raid.  In an attempt to reduce their own sentences, the other defendants claim Hanna bears the most responsibility, and that she wrote the report describing the event that is now in the hands of the prosecutors.  She doesn’t deny this, leading Michael at last to realise her secret: she is illiterate.  He is torn between telling the judge that Hanna is lying to protect her own pride, perhaps reducing her sentence, and respecting her wishes by keeping silent.  He is also devastated by the realisation that he has loved a woman who was complicit in the killing of innocent people.  Ultimately he decides not to get involved and Hanna is sentenced to life in prison.

In the years following the trial, Michael marries and has a daughter, but is soon separated from his wife. He is haunted by the conflicting guilt and desire he feels regarding Hanna.  After his divorce, he starts recording himself reading books on cassettes for her; this continues for a long time, but he never visits her or writes to her.  Hanna meanwhile teaches herself to read.  After eighteen years in prison, the parole board decide she can be released, and Michael agrees to help her find a job and somewhere to live.  He visits Hanna for the first time on her last day in prison; the next morning, she kills herself.  Michael is left to resolve his conflicts by himself.