In 1483, the Confraternity of the Immaculate Conception commissioned Leonardo da Vinci and Ambrogio and Evangelista de Predis to paint an altarpiece for their chapel in the church of San Francesco Grande in Milan. Due to a controversy regarding payment to the artists, it appears that the painting was never delivered. This episode will examine the controversy surrounding the two versions of the same subject – one in the Louvre, the other in the National Gallery in London.