Leonardo painted the Virgin of the Rocks twice, and neither version stayed with the monks who ordered it. This film retraces his walks through the mountains north of Milan to find the cave he put behind her.
In 1482 Leonardo left Florence for Milan carrying a letter that offered to build bridges, cannon and siege engines, most of it work he had never done. Duke Ludovico Sforza was unconvinced. What came instead was an altarpiece, shared with two local brothers, for a confraternity that wanted the Immaculate Conception painted. Nobody had yet worked out how you would paint it.
Leonardo's answer was a cave. Jean-Pierre Isbouts follows the roads and mule paths north of Milan, using Leonardo's own notes in the Codex Atlanticus, into the Grigna mountains with the collector Massimo Mazzoleni, whose family has owned one of those peaks for over a century. Above Lecco they climb to the Grotte di Laorca, then turn round and look out of it.
The finished painting was admired enough that Leonardo asked for more money, was refused, and sold it to somebody else. The Louvre has had it ever since. Years later he agreed to paint the scene again for the confraternity, and that second version hangs in London. In 2019 the National Gallery used X-ray fluorescence on it and found a completely different composition, drawn under the paint and then abandoned.
So the film has it painted. Gunnar Ahmer, who copied Michelangelo's Sistine ceiling for Angels and Demons, works up the London picture as Leonardo first sketched it, while curators from the Louvre, the Alte Pinakothek and the National Gallery argue over what he changed and why.