Number 12 in the series, a richly atmospheric tale set in Florence. Guarnaccia investiages the murder of Sara Hirsch, a spinster living alone at Villa L'Uliveto. The Columbo of Italy, Nabb's likeable Guarnaccia is not entirely at ease, a Sicilian living in Florence, but he's deceptively clever (and a solid citizen).  (ITL636, $12.00)