Every now and then I become infected with a deep-seated sense of longing. It saturates my days. I find it hiding in the shower stall, swimming in my cereal bowl, staring back at me from the black depths of my morning coffee. It is there, watching me, when I lace up my running shoes at 6am, and it is waiting in my bed when I pull on my pajamas at night. It sits quietly next to me on the drive...