Jennifer SilverbergQiu Xiaolong in 2007.Washington University professor and author Qiu Xiaolong is out with his latest detective novel. The book, The Mao Case, is the sixth installment of Qui's popular Inspector Chen series. In 2006 the Wall Street Journal named Qui's Death of a Red Heroine one of the best political novels of all time. Qiu will be signing copies of his new novel at 1 p.m. this Saturday at Big Sleep Books in the Central West End. Qiu was the subject of a 2007 profile