βBet Yer Blue Boonsβ is one of the most agile and intelligent cutting horses in the world, a true champion. βRio,β a spectacular polo pony, is a gifted athlete able to sprint at 30 miles per hour, then stop suddenly and turn on a dime. βChamontβ has the natural talent and physique of a great dressage horse, but also at times a timorous personality that puts a question mark on his future success. Each of these remarkable animals shares an astonishing trait: the ability to implicitly trust, and perform complex tasks in tandem with, a human partner working toward a common goal. This teaming of horse and rider is arguably the most sophisticated and intriguing example of human-animal cooperation. NATURE explores and illuminates this absorbing phenomenon in Horse and Rider.