In 1908, a newspaper organizes an endurance horse race through the desert: 700 miles to run in a few days. Nine adventurers are competing, among them a woman with unclear motives, a Mexican, an Englishman, a young gunfighter, an old cowboy and two friends from their days with the Rough Riders in Cuba, Sam Clayton and Luke Matthews - all matched against a thoroughbred backed by the race's sponsor. These individualists will be challenged to respect each other as the competition becomes increasingly brutal and strenuous.