Chance, volition, and the large effects of tiny causes swirl through Paris on a single day. A clerk born 11 March 1977 hears her horoscope on the way to work: today she'll meet her true love, but she must be patient. Before the day ends under a full moon, twenty lives intersect time and again in unpredictable, connected ways: a jilted lover holds a souvenir pebble, a stolen coffee maker looks suspicious at a Metro stop, a yellow rain slicker is passed on as a gift, lettuce causes a bicycle accident, a leaf betrays an habitual liar who's just told the truth, and an Algerian waiter, also born 11 March 1977, sees a bug cross a tablecloth. Magical sand from the Sahara is in the air.