Urbino Macintyre fights to protect the safety of his closest friendCenturies ago, Venice celebrated the Day of All Souls by building a bridge of boats across the canal to the cemetery island of San Michele. Contessa da Capo-Zendrini decides it's time to revive the tradition. Her plans are upended, however, when her latest fascination, a rakish playwright named Bobo, begins receiving anonymous threats. She begs her friend, the amateur sleuth Urbino Macintyre, to find out who has been sending the letters, only to discover that Bobo is implicated in a grisly murder. As the day of the black bridge draws closer, Macintyre scrambles to discover the true killer and keep his friend safe. If he doesn't act quickly, the contessa's journey to the cemetery may be a one-way trip.