“For any collector of Rembrandt, Russia is pretty close to Mecca,” says Thomas Kaplan, the owner of the largest number of paintings by the Dutch master in private hands. “The Hermitage is one of the greatest repositories of Dutch art in the world. If you are as enthralled with The Return of the Prodigal Son (1663–1669) as I am, then the Hermitage might as well be the Kaaba stone.” English.