12-year-old Jackie has made the Rijksmuseum her second home, since her mother works there. While Jackie’s wandering around after hours, Oopjen Coppit (from Rembrandt’s famous painting) suddenly appears in front of her; she’s looking for her long lost sister. Jackie’s used to solving other people’s problems and decides to take her home, so they can go look for her sister. For Oopjen, a woman from the Golden Age, the 21st century is a big adventure and Jackie finally gains a real friend: a true BFF.