Looking up in the sky an eerie blue light rolls into view. Before you dismiss it as an aeroplane or a satellite, it grows larger and larger, the spotlight flashes downward and surveys the terrain. You are amazed this is happening to you and you realise it is hovering over you; you barely make out its structure, but you feel it scanning you, knowing your presence, and aware you cannot budge. The aliens have arrived, and they've come for you.