Excursion to Tindari

The fifth in the hit Italian crime series by Andrea Camilleri, Excursion to Tindari is a darkly comic detective story featuring Inspector Montalbano.
Maybe a phrase, a line, a hint somewhere would reveal a reason, any reason, for the elderly couple's disappearance...
A young Don Juan is found murdered in front of his apartment building early one morning, and an elderly couple is reported missing after an excursion to the ancient site of Tindari - two seemingly unrelated cases for Inspector Montalbano to solve amid the daily complications of life at Vigata police headquarters.
But when Montalbano discovers that the couple and the murdered young man lived in the same building, his investigation stumbles onto Sicily's brutal 'New Mafia', which leads him down a path more evil and more far-reaching than any he has been down before.