Mohammad Khan enters the story at the Los Angeles airport, where he is being interrogated as he tries to return home to New York. Mo, as he calls himself, is an architect. He comes from a middle-class family and is the son of an engineer. Though of Muslim Indian lineage, he is very secular. He curtly answers the officers’ questions: No, he knows nothing about jihad. No, he’s never been to Afghanistan. No, he’s not a terrorist. After sorting through his bags, despoiling his toiletries, and asking him inane questions, airport security finally releases him.

After returning to New York, Mo heads toward Ground Zero, observing the dust particles and debris. He looks at the skyline as only an artist or architect can and feels nostalgia for the lost towers. He had felt indifferent to them, considering them representations of forward momentum, a rebuke to nostalgia, small business, and culturally vibrant streets and neighborhoods. But now he feels nostalgia for them, viewing the Manhattan skyline as an architectural collaboration between generations.

Claire flashes back to September 11, when her husband Cal was killed. She had been taking her anger out on him by swimming briskly in their pool. She recalls their joint decision that she would stay home after giving birth to their son, William, even though she felt it a waste of her Dartmouth education and Harvard law degree.