Maybe a phrase, a line, a hint somewhere would reveal a reason, any reason, for the elderly couple's disappearance. They'd saved everything ...there was even a copy of the 'certificate of living existence', that nadir of bureaucratic imbecility ...What was the 'protocol', to use a word dear to government offices? Did one simply write on a sheet of paper something like: 'I, the undersigned, Salvo Montalbano, hereby declare myself to be in existence', sign it, and turn it in to the appointed clerk?