One of the things Parker Livingstone loves about his apartment at 822 Fifth Avenue is that it reminds him of the vanished mother who left it to him. The old building seems almost immune to the passage of time: its foyer, its furnishings, its etiquette are from another era. And once Parker discovers an out-of-service elevator with room to sit and write, he finds he can escape from the present completely. Not so at his job as a junior literary agent,...