Aryee travels to the Americas, where the first canines evolved more than 30 million years ago. Starting with some playful but clumsy wolf pups, he discovers the traits shared by all members of the wider canine family and reveals why dogs are considered to be more intelligent than solitary predators like cats. Following their evolutionary journey, he meets super-furry foxes emerging from a snowy den, comes face-to-face with a pack of fully grown wolves and, in South America, tracks down the tallest wild dog on the planet, standing at over a meter high and known as a "fox on stilts."