Swan, Oliver’s 20th collection, is a slim, lovely volume that explores familiar themes right from the opening line, “What can I say that I have not said before?” In the pages that follow, Oliver goes into the woods, to the shore, and spends time in her home, where her dog Percy wakes her up too early and is always eager for attention. Oliver loves the dog’s antics as much as she loves the natural world, which she observes and records with great care. Many of these poems are among Oliver’s best, and they remind readers that beauty and happiness should be celebrated. In the title poem, Oliver describes a swan and asks these poignant questions: “And did you feel it, in your heart, how it pertained to everything? And have you too finally figured out what beauty is for?/ And have you changed your life?”