"The Return of the Mystical Lamb" seeks to pierce the mysteries of the work. The film starts on the return, after the 1940-45 war, in military trucks of the canvases that Goering had stolen from most European museums. In Brussels, at the Royal Museums of Fine Arts, each painting in the altarpiece is examined with magnifying glasses, microscopes, positive and negative photographic shots. Even more details than when it is re-exhibited in the church of Saint-Bavon. The whole of the altarpiece put back into circulation will make it possible to discover something other than what the trappings of the technique offer.