While posted in London in the early eighteenth century, Austrian captain and spy, Phillipe Wolf meets Catherine Barton, Isaac Newton’s niece. Wolf, also an amateur composer, endeavors to compose a concerto to impress the music-loving and intellectually provocative Barton. His concerto requires a perfect violin to match the music. To create the violin, Wolf enlists the help of the brilliant but prickly Newton, and the affable but secretive Antonio Stradivari, the famous luthier who lives in Cremona, Italy. Wolf must gain the trust of Newton and Stradivari by first understanding their genius, a task which often seems impossible.
The backdrop of the story is the War of Spanish Succession, which adds to the obstacles Wolf encounters in his quest. In Newton’s London, Wolf is drawn into political conflicts over the war, as well as a dangerous personal rivalry. Further complicating Wolf’s obsession, Barton is torn between her affection for Wolf and her obligations to her uncle. In Cremona, Italy, Wolf is on a perilous spying mission, which endangers not only himself, but also Stradivari and his family.