"American expat Kate Moore drops her kids at the international school, makes her rounds of chores, and meets her husband Dexter at their regular café. Across the Seine, tech CEO Hunter Forsyth stands on his balcony, wondering why his police escort just departed, and frustrated that his cell service has cut out. And on the nearby rue de Rivoli, Mahmoud Khalid climbs out of a van, elbows his way into the museum courtyard, sets down his metal briefcase,...