As Christie's celebrates its 250th anniversary, this two-part series follows the drama behind iconic art auctions across the globe to reveal how the world's biggest auction house operates.- Wanda's world has been turned upside down when her teenage daughter Nina suddenly turns up in a hijab. Secretly, Nina has converted to Islam; she exclusively eats halal, strictly observes the prayer times and wishes to be called Fatima. Mother of a liberal Viennese patchwork family, Wanda is appalled; she has always st…