Offered only the thinnest exposition and confronted with the details of four parents and six children, you may find yourself grasping for a dramatis personae. Indeed, for many pages, reading “Commonwealth” feels like being somebody’s baffled second husband at a family reunion. Who are all these people? How is he related to her? Whose child is that? Even Franny admits that “she couldn’t follow all the lines out in every direction: all the people to whom she was by marriage mysteriously related.”

Frankly, I was relieved to know I wasn’t the only reader who struggled with this.