Detective Stephen Moran hasn't seen Holly Mackey since she was a nine-year-old witness to the events of Faithful Place. Now she's 16 and she's shown up outside his squad room, with a photograph and a story. The previous year, Christopher Harper, from the neighbouring boys' school, was found murdered on the grounds. And today, in the Secret Place - the school noticeboard where girls can pin up their secrets anonymously - Holly found the photograph. Solving this case could take Stephen onto the Murder Squad. But to get that solved he will have to find a way into the strange, charged, mysterious world that Holly and her three closest friends inhabit and disentangle the truth from their knot of secrets.