The first part of the novel focuses on Mrs. Morel and her unhappy marriage to a drinking miner. She has many arguments with her husband, some of which have painful results: on separate occasions, she is locked out of the house and hit in the head with a drawer. Estranged from her husband, Mrs. Morel takes comfort in her four children, especially her sons. Her oldest son, William, is her favorite, and she is very upset when he takes a job in London and moves away from the family. When William sickens and dies a few years later, she is crushed, not even noticing the rest of her children until she almost loses Paul, her second son, as well. From that point on, Paul becomes the focus of her life, and the two seem to live for each other.
Paul falls in love with Miriam Leivers, who lives on a farm not too far from the Morel family. They carry on a very intimate, but purely platonic, relationship for many years. Mrs. Morel does not approve of Miriam, and this may be the main reason that Paul does not marry her. He constantly wavers in his feelings toward her.
Paul meets Clara Dawes, a suffragette who is separated from her husband, through Miriam. As he becomes closer with Clara and they begin to discuss his relationship with Miriam, she tells him that he should consider consummating their love and he returns to Miriam to see how she feels.
Paul and Miriam sleep together and are briefly happy, but shortly afterward Paul decides that he does not want to marry Miriam, and so he breaks off with her. She still feels that his soul belongs to her, and, in part agrees reluctantly. He realizes that he loves his mother most, however.
After breaking off his relationship with Miriam, Paul begins to spend more time with Clara and they begin an extremely passionate affair. However, she does not want to divorce her husband Baxter, and so they can never be married. Paul’s mother falls ill and he devotes much of his time to caring for her. When she finally dies, he is broken-hearted and, after a final plea from Miriam, goes off alone at the end of the novel.