In October 2019, the Louvre opened an unprecedented exhibition of works by Leonardo da Vinci. The show marked 500 years since the death of the Renaissance master and it was the largest-ever collection of his works brought together in one place. After more than ten years of research and planning, the once-in-a-lifetime exhibition offered an exhaustive catalogue of da Vinci’s oeuvre and set a record for attendance. One excluded painting, though, is a problematic footnote.