Two authors working on one novel usually manage to strain against the wagon shafts as in this uncoordinated but well-intentioned effort to substantiate the innovative art of Caravaggio, the 16th century Italian painter. While on one level la vie boheme proceeds apace -- brawling, bedding, roistering -- another explores the concept of the creative process, as Caravaggio's Armageddon chiaroscuros emerge from the canvas. Predictably the authors focus on the painter's break from the schooled geometry of the post-Michelangelo cliques and into the drama of light (""We see only what our eyes reach for""). Unfortunately the fountainhead of this aesthetic vision becomes wearisome after one viewing. Caravaggio paints, loves, and confronts his peers and betters with the same stormy glower. The story begins with his youthful arrival in Rome and his adoption by a man of influence; then the frenzied artist's life, early experimentation, the scorn of popular artists and the drift from patron to patron and love to love -- his model, an aristocratic lady, and also poor Beatrice Cenci who gives birth to his child before her execution for complicity in her father's murder. All this is set against ecclesiastical politics and a rapid succession of popes. While a respectable effort in this popular genre, The Goliath Head is still a Stone's throw away from that kind of success.