One evening late in his life, veteran sportswriter Mike Sullivan was asked by his son what he remembered best from his three decades in the press box. The answer came as a surprise. "I was at Secretariat's Derby, in '73. That was . . . just beauty, you know?"Sullivan didn't know, not really: the track had always been a place his father disappeared to once a year on business, a source of souvenir glasses and inscrutable passions in his Kentucky relatives. But in 2000, Sullivan, an editor and essayist for Harper's, decided to educate himself. He spent two years following the horse-both across the country, as he watched one season's juvenile crop prepare for the Triple Crown, and through time, as he tracked the animal's constant evolution in literature and art, from the ponies that appeared on the walls of European caves 30,000 years ago, to the mounts that carried the Indo-European language to the edges of the Old World, to the finely tuned but fragile yearlings that are auctioned off for millions of dollars apiece every spring and fall. The result is a witty, encyclopedic, and in the end profound meditation on what Edwin Muir called our "long-lost archaic companionship" with the horse. Incorporating elements of memoir and reportage, the Wunderkammer and the picture gallery, Blood Horses lets us see--as we have never seen before--the animal that, more than any other, made us who we are.