I found this to be a bit of a tough read. It's written in 3 parts, and part 2 really turned me off, so it took me a lot longer than it should have to finish. I've never seen then movie, but now that I've finished the book, I think it might be interesting. Someday. I'm gonna go out to rent it right now or anything.
So it's written in the voice of the main character, Michael Berg, looking back on this particular part of his life. The first part of the book covers how Michael met Hanna Schmitz. When Michael was 15 he fell ill with hepatitis on his way home from school one day. He threw up in the road, and Hanna rescued him, cleaned him up, and took him home. He was sick for months and when he finally was well enough to, his mother sent him to find the woman and thank her for helping him. He did, and went back a few more times, and they end up having an affair, despite her being more than twice his age. She frequently asks him to read to her, which he does, and it becomes an integral part of their relationship. He doesn't tell anyone about their affair, not even his closest friends. I'm not sure exactly how long it lasts, but not much more than a year. Michael starts to feel as if he's betrayed Hanna because he can't bring himself to tell anyone about her, and he starts to want to spend more time with his friends. Then one day, Hanna disappears. He's completely distraught and depressed, but does very well to hide it from him family and friends.
In part two he goes on to college and studies law, thinking that he'd like to be a lawyer. A particular concentration of their studies is war crimes and ex-Nazis and how they should have been or should be punished for their crimes, and part of the course involves sitting through an actual trial. At the trial Michael sees Hanna for the first time in years and discovers that she was a guard in the concentration camps. He sits through every day of the trial, and after hearing stories and putting some pieces together, realizes that Hanna is illiterate. He feels this should have some effect on her case, but doesn't want to speak to her in person, and doesn't feel he can speak to the judge on her behalf. She gets sentenced to life in prison, and he goes on to marry a classmate. They have a daughter, and get divorced a few years later because Michael is constantly comparing the women in his life to Hanna.
In part three, Michael starts reading the books he had read in school, but finds that he has to read them aloud to fulfill whatever need he can't seem to satisfy any other way. And he starts recording his readings and sending them to Hanna in prison. At one point he also writes a book and sends her the recording. He's stunned when she writes him a note thanking him. He never writes back, but continues sending recordings, and she continues sending short notes. Then he gets a letter from her warden saying that she will probably be released soon and since he is the only person Hanna has contact with on the outside, it would be nice if he could arrange for a place for her to live and work, etc and be a support to her when she's released, because reintegration into society after 18 years of imprisonment is difficult, but especially for someone who's had no contact with the outside. Michael does provide these arrangements, and then it comes time for him to go to the prison to see Hanna and speak to the warden in person. Seeing Hanna is a shocking experience for him - she has aged so. He's torn over his feelings for her. She's still his Hanna, and yet she's older, she did terrible things during the war, she did terrible things in her life to cover the fact that she was illiterate, but then she did make the necessary sacrifices to learn to read and write while she was in prison. And though he knows why she left, he never forgave her for abandoning him without explanation or saying goodbye. Finally, the day before he's to pick her up, he calls the prison to speak to the warden and does speak to Hanna. The next day when he arrives at the prison, he's told that Hanna hanged herself early that morning.
The story gets wrapped up by Hanna leaving all her money to a concentration camp survivor and Michael finally learning to let go of her.