All love stories unfold according to the same familiar rules. So do I-love-New-York stories. In the classic tale, you have a mad-hot affair with Manhattan in your 20s-wild nights, poetic mornings, fabulous people, brilliant cultural events. Then you flee to the suburbs and buy a house with a yard, having decided that the city is not a marriage-and-family type of town. But you never forget it. When William Sofield met the couple whose apartment he would ultimately spend the next two years designing, they were on the cusp of reuniting with the city they’d left behind. '“We had made a commitment to each other that when our kids went to college, we'd return,” says the husband. When the time came. “We ran back.”