Kevin has never had friends. Connecting with others has been hard, and he has spent his life tormented by fear of the rest of the world. His mother, Rachel, tries her best, but she cannot change his developmental disability. That is far from her only problem; she and her husband, Brian, struggle to make ends meet, and although she hasn't told him yet, she is pregnant. For his eighth birthday, Kevin asks for piano lessons. His father disapproves, but Rachel makes it happen. He walks alone to his first lesson with Anita Tanizaki, his teacher, and they start with the basics. Kevin is overjoyed. Every other week, he goes back to learn more, and becomes increasingly comfortable with Mrs. Tanizaki and her house in the process. She even loans him her first piano book to practice, but Kevin has no piano at home to use. Instead, he draws a keyboard on a piece of paper and, for hours every night, taps away. In the meantime, Brian pulls away. After Rachel tells him and Kevin about her pregnancy, he starts to spend more time away from home until one day, he is gone. A month passes before he returns, and after an emotional conversation, he leaves for good. Rachel feels like she's drowning in worry. She has no idea what she will do when the baby comes. One day, Mrs. Tanizaki has her indolent son, Lawrence, play Kevin a piece that she wants him to learn. When he cannot match the teenager's performance, Kevin becomes distraught. He goes home to find his mother dazed—Brian has left for good—and tells her that he can't go back to his lessons. He feels isolated and inadequate, but, through her tears, his mother comes over and hugs him. She won't let him quit.