Ritual of Fire continues the exploits of Cesare Aldo, an officer of the Otto, a criminal court in 16^th Century Florence. The stench of the city and the corruption of the wealthy have followed Aldo out to the nearby Tuscan countryside. He has been in part banished, and in part has chosen to go, as his partner at the Otto, Constable Carlo Strocchi, struggles to accept Aldo as he is. Strocchi has declared either he or Aldo must leave Florence.

Added to the stench and corruption is the sweltering heat – both from a relentless summer, and from the roaring flames engulfing buildings and bodies. There are horrendous murders taking place, both in Florence where Strocchi works, and in Aldo’s village of San Jacopo al Girone. Are the murders connected? And if so, how? And are the notices being posted around the city linking them to the return of the 40-years-since martyred monk Savonarola – “the best and worst thing that ever happened to the city” – a clue, or a distraction?

For the masses, “roasting beneath the remorseless sun” and suspicious of their new young ruler Cosimo de’ Medici, the notices are tinder that sets them alight with religious fervour. As the sun boils the city and the countryside, Aldo and Strocchi race to solve the murders, and to stop more taking place. It soon becomes apparent that the victims are all linked – to members of a banned confraternity with which readers of previous books in the series will be familiar, a confraternity that had the dastardly Girolamo Ruggerio as one of its founders.

The plotting of Ritual of Fire is tight, and it is complicated by both the political ostracization of Aldo, and by Strocchi’s stubbornness in refusing to include Aldo in his investigations. Strocchi has hardened a bit since earlier instalments, and he is on his way up. But he is a walking zombie for parts of the story, having a 6-month-old baby keeping him awake at all hours. And when Aldo does return briefly to Florence, escorting a thief to the Otto, he finds he has lost his slick city ways, alienating both his superior, Massimo Bindi, and potential information sources. And then there is the complication of Aldo’s bond with Dr Saul Orvieto – their relationship at once a haven and another problem to be solved.

Despite neither Aldo nor Strocchi being at the top of their game, and the fact that “conscience and guilt were a swollen river between them”, both men do make progress. And the reader picks up clues as the story moves to its gripping denouement. The writing is a little repetitive at times – we are frequently reminded that in Florence, information and secrets are more valued that gold – but it is very atmospheric: “Ruggerio had sensed a gathering threat, like the first aroma of burning as sparks catch hold of tinder.”

One of the themes in the story is the danger of enlisting groups of young men to causes. No matter how worthy the cause, once young men are put in positions of power, bad things will surely follow. The resolution to the mystery is as disturbing as it should be given the horror of the crimes. And there is hope that Aldo and Strocchi will soon be once again pounding the beat in the political tinderbox of Renaissance Florence. And I look forward to reading more of their adventures when they are.