I’ve read similar stories based on hidden messages in Leonardo da Vinci’s masterpieces and this one provided additional information I’d not yet read. It involves the Last Supper mural in Milan and the Pope’s secret inquisition into it while da Vinci is still working on it.
It is a fictional historical thriller similar to Dan Brown’s novels which I enjoyed. Stories like these fascinate me. If you enjoy them also, I think you will like this. I will never look at the Last Supper painting in the same way again!