"Number Theory," by Rosanna Warren

The four-and-a-half-foot black-backed rat snake swayed up and across the kitchen screen door, seeking a way in. So we know we're living with a patient You sit taut in your chair, whispering, as you probe the gaps between prime numbers. The opening through which your thought will glide suddenly into a lit space and be at home. In a shaky house, where wasps gnaw the walls.