Chinese mid-career artist Cao Fei’s “HX” is one of her most ambitious projects so far that transfer her studio，the former Hongxia Theatre located in 798 art district as a new stage of art creation. This velvet covered artist book reveals the hidden histories of Hongxia under social changes in China over the last 8 decades. The HX’s matrix  lies in its images that compiled in the form of an ‘atlas’：archives from different sources，document photographs of Hongxia building， screenshots from her Nova project and such. This artist/photo book integrated Cao Fei’s recent practices in photography， film，digital media and performance，as editors put，transcends the significance of the HX project itself. It expands to a wider consideration of the past and its relationship to our contemporary world.