" He turned down the street to Emilio's, trying to remember what "the edge of chaos" meant. It was something about flipping a coin, something about the edge being the moment when the coin was in the air. The point at which the system was pure potential, about to choose a path. Or something about a pile of sand, adding sand a grain at a time, and the edge of chaos being the point at which the critical grain landed and the pile either shifted or turned into an avalanche...
...Min bit her lip and smiled at him ruefully, and without another thought, he walked across the room to her, feeling almost relieved as the avalanche began. "

― Jennifer Crusie , Bet Me