Every afternoon, I drive to my local YMCA and spend an hour jogging in place on an elliptical machine. At that time of day, I am not in the mood to chat with my neighbors, churning away at their own machines, or even to gaze at the images on the screen before me. I instead turbo-charge my elliptical run and open a book. I am all business.

But a couple of weeks ago, my eyes kept wandering from the book I had brought—a play that my students were reading in one of my classes—to a fellow Y regular. I had noticed her many times before but had not paid her much attention. Wearing the same garb every day—a white and blue sailor’s shirt and baggy, blue jeans—she always circled the gym with small weights in both hands, frequently halting her orbit to chat briefly with another gym member. It was always the same. The width of her gyre never changed.

Her routine, which I first found intriguing, began to make me uneasy. Why did I see her, as if for the first time, only now? It no doubt had something to do with the book I had brought with me that day. As I looked down at one of the dog-eared pages, I reread an exchange between the play’s two principal characters, Vladimir (Didi) and Estragon (Gogo):