It is Coronation Day 1902 and it is seven year old Sarah McMillan's last day alive. Eye witnesses confirm that she spent the day playing with her best friend on the streets of Pelaw Quay, an industrial settlement in north eastern England. She vanishes on her way home in the early evening and two days later, after frantic searching, she is finally found in a shallow grave. She has been brutally murdered. A local police team investigate the confused and contradictory events of the day and they soon make an arrest of a local man - a soldier - who is tried and hanged. But was he the real murderer or an innocent dupe?
A century later a young author sits down to write a book about the crime, and what begins as an apparently straightforward tale of an historical rush to judgement takes on some altogether stranger twists.