Hannah twirled her pencil in her fingers and stared vacantly at her notebook. It was amazingly unlikely that they ever would have met in the first place, so it shouldn’t unsettle her to know she would never see him again after the semester’s end. It shouldn’t, but it did. She had been unfathomably lucky. Of the six billion people alive today, the one hundred billion dead buried beneath the parking lots under their feet, and the uncountable trillions who would ever live, Hannah happened to exist in the same country, state, and city, in the same fingernail sliver of the present on the infinite landscape of time, as he did. How fortunate that they were enveloped in the same language and socioeconomic bracket, attending the same school, taking the same English class, and each had a predilection for sitting in the rear left of a classroom. The odds against their meeting - he, an infinitely improbable product of the incalculable potential combinations of his parents’ genes, and Hannah, an equally improbable mixture of her own two parents - were staggering, so staggering it made Hannah’s head throb with delicious pain just thinking about it.

Yet she had defied those odds in that cramped, weathered classroom on that little spinning blue planet, and once she had even summoned the courage to look at his eyes. Hazel. How many factors must be delicately, perfectly calibrated for her to glance into those eyes, for her even to exist to glance into those eyes? A single letter grade on a single English paper, a single step to the left, a single misplaced grain of sand on a beach in Norway three thousand years ago could make the difference between her marrying him and her living out her life oblivious to his existence. Did she chalk it up to God? Hannah wasn’t sure, but she found the thought of astoundingly unlikely blind chance much more philosophically exciting. The mere fact that she was alive and could sit silently near him every day was like hitting the cosmic lottery. But her winnings would soon evaporate when the frail, quivering threads that tenuously bound their lives so briefly together finally unraveled, and he vanished into the opaque darkness of the future.

Hannah took small comfort in the fact that as they sat together in their tiny plastic seats, on the periphery of mutual acknowledgment of each other’s existence, they were both losing six hundred thousand skin cells every hour. By the end of the term, there would be an invisible half pound of each of them left behind. Even when he was gone and this building was boarded up and forgotten - even when they and everyone who remembered them turned to dust - microscopic pieces of her and microscopic pieces of him would linger together in that dark, silent classroom forever. Hannah looked up from her notebook and smiled at him.