For only the fourth time in two centuries, the French have agreed to allow the Mona Lisa to leave the Louve, this time at the request of the pope who wants to display it in the Vatican Museum. However, after it’s placed on display, the museum’s former curator notices almost imperceptible discrepancies in the fabled masterpiece that leads to the discovery that the painting on exhibition is a forgery. The question is: did the French not trust the Vatican with the real Leonardo da Vinci masterpiece and send this clever fake, or did someone steal and replace the original? The pope, not wanting to ask the French if they sent the authentic painting, turns to Mauro Bruno and his associates at BD&D Investigations, who’d helped the Vatican in the past, to answer that question without alerting anyone that the real painting is missing.

As they begin their investigation, Bruno and his colleagues discover that the Mona Lisa isn’t the only masterpiece that’s gone missing and not reported. Other museums, in addition to the Louve, have had major works of art systematically replaced with brilliant forgeries. These thefts were almost never reported because of the museum’s belief that the public and their donors would lose confidence in their managers and directors, resulting in a drop in attendance and withdrawal of donor funding. More bewildering was that a ransom has never been demanded for the return of any piece of art, all of which were so unique and recognizable that they would be extremely difficult to sell.

As their investigation intensifies across three continents, Bruno and his team discover that a single person they call the Collector is behind these thefts and that, if not caught soon, plans to take their masterpieces and disappear into obscurity.