A local shop is burned down in a clear case of arson. Its owner seems to have disappeared into thin air. Montalbano investigates, but is also kept busy by multiple reports of strange kidnappings in which female victims are abducted and released unharmed shortly after, with all of their possessions untouched and for no apparent reason.

A former prostitute has disappeared. Her sister tells Montalbano that she had recently fallen in love, so the police start their investigation by speaking to her lover, a meek and gentle man who is puzzled about where his partner could have possibly gone.