In 1425 the building of the great dome of Florence cathedral is reaching a critical point. Filippo Brunelleschi, an irascible genius, is in charge of its construction, watched over by his patron, the powerful banker Cosimo de' Medici. Young Assistant Building Supervisor Luca da Posara can't think of anywhere else in the world that he'd rather be: it's the birth of the Renaissance and the very air seems alive with fresh ideas, in science, philosophy, art and architecture. But then he finds the body of a visiting mathematician, brutally murdered. Papers on the corpse allege that Filippo Brunelleschi stole his ideas. Who had him murdered? Filippo or Cosimo? Or the hot-headed sculptor Donatello, Filippo's closest friend? Or one of their bitter artistic or political rivals, to destroy Filippo and discredit Cosimo? After a second killing, Luca feels compelled to turn amateur detective - and discovers it's all a matter of perspective.