In the book "Sula" by Toni Morrison Plum is Eva's son whom she dearly loves. She sees the torment he is experiencing in his life. Ralph is her youngest child. He became internally and psychologically damaged after fighting in World War I. Since his return home he has been a heroin addict and an alcoholic. He has stolen from his mother to purchase drugs and alcohol. Eva watches her son’s daily slow self-destruction, and she is so emotionally pained by his suffering. While he is high she pours gasoline over him and sets him on fire, killing him. She has given him a mother's peace in the only way that she knew how to help Plum.
Eva truly loves Plum and she understands what kind of a messed up life Plum is living. Because of this she wants to end his pain and his addiction to heroin at the same time. He is damaged from the war and Eva slowly watches her son turn into a wreck. Because of this she takes things into her own hands and kills him in order to let him get away from this madness.