Luke is a 12-year-old who encounters some weird situations one day. He and his two friends go about investigating the events, while also navigating the demands at school. They find an old, abandoned library which they explore and find a book outlining an alien invasion. An unusual sighting which could have been a UFO. One of their school mates behaves weirdly and they follow him one day to discover an unsettling secret. A mysterious person had disappeared in unexplained circumstances a few years earlier and appeared to be linked to the weird events. A clue pointed to the Glencoe highlands in Scotland. A happy coincidence occurred when his parents plan a holiday to Scotland. Things come to a head in a series of adventurous events which finally leads them to the truth about the aliens.