Veteran actor Tuccio Musumeci makes his second cameo appearance on Montalbano in the role of Liborio Pintacuda, a retired Professor of Philosophy. The previous one had been in Il Camp del Vasaio (The Potter's Field), and on that occasion he had a casual encounter with Salvo over dinner, and they then spent time fishing together. This time, he happens to also be someone who long ago knew the people in one of the sub-plots. Salvo clearly enjoys his company and his words of wisdom.