A bomb goes off outside an empty store-room in a quiet Vigata street. Montalbano commences his investigation, but is soon disorientated by a series of disparate events, including the acquaintance of an attractive and mysterious woman.

A woman is attacked and robbed on her way home late at night, but the case leaves Montalbano wondering whether there isn't more to the story than he's being told. An abandoned cattle shed in the countryside has been boarded up by unknowns and used for mysterious purposes.