Leopards are the supreme masters of stealth and camouflage. Secretive and elusive, they're also the least known of all Africa's big cats. Rarely active in the daytime, they're creatures of the night and this has made them impossible to observe by film-makers or scientists - until now. This programme follows a scientist in Namibia as he works with bushmen to unravel the leopard's secrets. And state-of-the-art video equipment is used in Zambia's South Luangwa Valley to obtain unique images of the leopard's night-time world. Combined with an amazing soundtrack, the tension and suspense of the night is revealed for the first time as the antelope try to survive the long hours of darkness stalked by these most extraordinary cats.