The secret lives of the worlds most mysterious cats are brought to light by advances in remote and low-light filming technology. In South Africa, we follow the nocturnal pursuits of the tiny black-footed cat that stakes its claim to the title of the world's deadliest, and in remotest Mongolia we reveal the rarely seen Pallas's cat, at home with her kittens - she hunts by looking like a rock. Finally, in South Africa, we uncover the secret of the serval that thrives amongst the futuristic landscape of Africa's biggest industrial complex. These are remarkable cats, with surprising lives in extraordinary places.