Art of Change: New Directions from China, Hayward Gallery, London I am being followed around the gallery by a young Chinese woman. She remains a metre behind me at all times, mirroring my movements, watchful and silent. Her hair is cut in a bob and she wears what appears to be a striped prison uniform. When I turn to look at her, she turns too. She refuses all eye contact. Her body seems floppy, docile, as though drugged. Far from passive, however, she is surveying me with intent. But that intent is never stated. Like a menacing shadow, she is simply there, and then, after about an hour, she disappears. This is the work of Shanghai-based conceptual artist Xu Chen, "CEO" of "cultural production" company Madein (a play on "made in China"). First performed in 2002, the piece marks the opening of this sensational new exhibition, comprised mostly of xingwei-zhuanzhi, or performance installation art, from 1993 to the present day. Developed under conditions of censorship, the genre - experimental, live, action-based - was ephemeral by necessity. It had to elude the state. Nine Chinese artists, spanning two generations and a range of mediums, are united by ideas of flux, metamorphosis, and transition. The principle of change is key to Taoism; it also resonates with China's economic transformation and the trauma of the Cultural Revolution. Here that principle is used to spectacularly unnerving - and beautiful - effect. Accompanied by my new friend, I crawl through an Alice in Wonderland size doorway into a darkened room lined with barren trees. At the far end, a woman is singing. It is the Germany-based artist Yingmei Duan. She is wearing a white dress and smiling at me in a very disconcerting way. The experience is akin to wandering into someone else's deranged psyche. Duan gives me a hand-written note which describes her time living with "a polygamy family in Swaziland." Over the course of the exhibition, she will be offering "wishes" for viewer-participants to fulfil. Elsewhere, Liang Shaoji provides a Zen space in which silk-worms can be heard spinning their thread, Xu Zhen suspends a person in free-fall, as if by magic, and Chen Zhen has covered a whole room in mud. The other artists are Gu Dexin, Wang Jianwei, Sun Yuan and Peng Yu. A notable absence is Ai Weiwei. As my stalker shifts from subservience to a more predatory attitude, I am unsettled. This seems to be the point. Much of the art here is outstanding.