In 1950s Manhattan, violin dealer Thomas Barlow receives an unexpected visit from an old friend and fellow WWII veteran Jonathan DeWitt, who is seeking his appraisal for an old Italian cello. The cello is purported to be the work of Andrea Guarneri, a famous luthier from Cremona. The deeper Barlow dives into the cello's past, the more certain he becomes that it is not the work of Andrea Guarneri. This revelation propels him unrelentingly toward the confrontation he has tried for years to avoid with DeWitt, with whom he shares a dangerous secret he thought remained buried in war-torn Europe.

In 1693 Italy, Pietro Guarneri emerges from an unspeakable personal tragedy to find himself ensnared in a treacherous political web due to the meddling of his employer, the Duchess Gonzaga of Mantua. With the sole aim of protecting his family and concealing the identity of Elena, the apprentice he smuggles into his workshop to teach, Pietro reluctantly begins constructing the only cello of his instrument-making career. The result will alter the foundations of Pietro's life and reverberate through the centuries, shrouding the truth of the cello's origins in secrecy.