This is, I believe, the second of Lucretia Grindle's thrillers set in Florence. I am reading them in the wrong order having read Villa Triste first. They only share one character in common, the detective, Pallioti, and his role in this book is less important than in Villa Triste.
The story is told by Mary Warren, an American, and we see everything from her point of view. She has been the victim of a near fatal attack in the Boboli Gardens during which, in an attempt to save her, her husband has been murdered. Two years later, the suspected murderer having been killed in a car crash, she has returned to Florence to be with her lover. She is studying History of Art and sharing a flat with a fellow student, Billy (a woman). She is not open with her fellow students and we begin to have doubts as to whether she is being totally open with us. As other murders come to light, it appears that Mary may have been the victim of a serial killer and not the suspect the police had arrested. Information comes out slowly and unwillingly. As Mary says, she is a very private person and she does not want her life to be controlled by her attacker. Billy is interested in Mary, suspecting there is a mystery and (she says) by googling her, discovers what has happened. She needles and teases Mary until she opens up and reveals what has happened. For Mary, the past is the past, but Billy wants to open things up and discover what has happened. There are more deaths and multiple suspects, among them Mary's lover, two of her fellow students and a priest.
In the end the crimes are solved but a feeling of disquiet remains. The characterisation is very strong. Mary is a complex and not totally sympathetic character. Billy, although anxious to find out the truth, can be difficult and unpleasant. Mary's lover seems too good to be true. The priesthood, as exemplified by members of Opus Dei, is sinister and threatening, but completely credible. (This book is far more effectively derogatory about Opus Dei and its influence on the church than the Da Vinci Code is.) Clichés and stereotypes are avoided. The villain was on my list of suspects, but was not the most obvious.
This is a very powerful thriller. I was completely enthralled but it is not always an enjoyable read.