Alien overlords have peacefully invaded Earth, promising to usher in an era of peace, health and security by eliminating poverty, war and sickness. There are questions, however, about the overlords and their intentions, such as why they insist on hiding their appearance and what they ultimately want from the people of Earth. While most people enjoy their new utopia, some suspect that there will be a price to pay. As the overlords' true intentions are unravelled, humanity realises that its destiny may be more of a nightmare than a dream. This miniseries is adapted from Arthur C. Clarke's 1953 book of the same name.