The poems in "Hummingbird Sleep" move associatively between Coleman Barks's personal experience and his extensive reading, weaving together a wild and eclectic range of material. A discussion of Plotinus, Barks's appearance on PBS "NewsHour," a note Keats once left on Wordsworth's mantelpiece, a splinter in the heel, and a quote from the Upanishads-all make their way into Barks's most recent poems, which achieve intimacy and expansiveness at the same time.