The TV series "The Gathering" tells the story of the investigation into a brutal attack in Northwest England. On an island in Merseyside County, a rave is taking place, attended by teenagers from different social backgrounds who have come from all over the country with their families. However, in the midst of the celebration, someone kills one of the young girls. A small group, including both her peers and their parents, becomes the prime suspects as they had interacted with the victim. The police discover that many of them had motives.