Natural history series about wildlife at night culminates at the wild and windswept tip of South America. Coming face-to-face with the widest-ranging cat in the Americas - the puma - camerawoman Justine Evans attempts to film their nocturnal hunting behaviour for the first time. Even further south, Gordon Buchanan dives into the icy waters of the Strait of Magellan to solve a mystery - scientists have heard humpback whales moving close to the shore at night but have no idea what they could be doing. And Dr George McGavin attaches a miniature tracking device to a vampire bat's back to discover whose blood it is feeding on.