They started leaving the apartment. One day they drove to Federal Hill to have pizza. Afterward, Leonard insisted that they go into a cheese shop. It was dark inside, the shades drwan. The smell was a presence in the room. Behind the counter, an old white-haired man was busy doing something they couldn't see. "It's eight degrees out," Leonard whispered, "and this guy won't open the windows. That's because he's got a perfect bacterial mix in here and he doesn't want to let it out. I read a paper where these chemists from Cornell identified two hundred different strains of bacteria in a tub of rennet. It's an aerobic reaction, so whatever's in the air affects the flavor. Italians know all that instinctively. This guy doesn't even know what he knows."