Based on a chilling true crime, The Monster of Florence follows the reopening of a cold case—a serial killer who targeted unmarried couples and terrorized Florence for two decades.

Marshal Guarnaccia's job with the carabinieri—the local Florentine police—usually involves restoring stolen handbags to grateful old ladies and lost cameras to bewildered tourists. So when he is assigned to work with the police to try to track down a vicious serial killer, he feels out of his league. To make matters worse, the prosecutor he must report to is Simonetti, the same man he knows drove an innocent man to suicide several years earlier in his blind quest for a conviction. The marshal can't let the stress of the case get to him if he wants to make sure justice is upheld.