I'm always eager to find a new voice; at the same time, I can be demanding, so then my reading world becomes a little echo chamber, a home *only* for Ruth Rendell and Anne Tyler. "Good Company"--a splashy new novel by Cynthia D'Aprix Sweeney--has at least a few memorable characters. There is Margot, who has a prominent role on a long-running "ER"-ish show, and whose character must die "for ratings reasons." Margot sort of likes fame, but she hates having to sanitize her past, in interviews, and she doesn't love when the bossy costume-designer hovers near the snack table. ("You're having bread AND pasta salad.....?") Margot complains about paparazzi, but also, if no one is noticing her in a crowd, she might dramatically drop her handbag as a way of calling attention to herself. Margot's good friend Flora has had less success in the performance world, and she decides to give up when she finds herself bored in the chorus of Broa...