On a scorching summer afternoon in the suburbs of Florence, a small girl goes missing at a crowded swimming pool and is never seen alive again. For fifteen years a terrible crime lies unsolved, becoming one of the city's darkest and most shameful secrets, until one bitter winter night another body is found, at another swimming pool, and the case is reopened.

Celia Donnelly had just arrived in Florence at the time of the girl's disappearance and can remember only too well the face that filled the front pages of every Italian newspaper. When word of the gruesome new discovery breaks, she is in the midst of arranging a weekend of birthday celebrations for a wealthy Englishman's wife. However, as Celia undertakes what ought to be a routine work assignment, she finds herself more closely involved than she could have ever imagined with a tragedy that has haunted her dreams for fifteen years; and it is Celia who is compelled to bear witness when the past returns to exact a brutal and terrifying revenge.