Well into his middle years, Gianni Castiglione has a pleasant, quiet life in Cremona. A luther - a maker and repairer of violinis - he spends most of his time adoring his grandchildren and playing chamber-quartets with the local priest, the chief of police, and a fellow aging luther, Tomaso Rainaldi. A true romantic, Rainaldi is in thrall to music's myths, particularly the stories about the "Messiah's Sister," a priceless, centuries-old -- and possibly imaginary -- violin. But his end is anything but romantic; the old fellow is brutally murdered and his workroom destroyed. It soon becomes clear that Rainaldi's violins has something to do with his death, and while the police-chief knows little about the luthier's world, Gianni has the knowledge he needs. Following the clues will take the two men into a decaying Venetian palazzo, to an English country estate, and deep into musical history, as they hunt for a secretive collector, a collection of letters, a mysterious portrait, and, perhaps...the Messiah's Sister itself.