The latest works on sensitive Chinese topics by Hong Kong publishers went on show at a book fair this week, despite the chill persisting from recent detentions of five local booksellers.
The former British colony has a lively market for so-called banned books, covering Chinese elite politics and other topics off-limits to mainland readers. The temporary disappearances of the five men, who worked for the publishing firm Mighty Current, highlighted fears Beijing is tightening its grip on Hong Kong.
Hong Kong returned to Chinese control in 1997, but its semi-autonomous government has preserved civil liberties such as freedom of speech that for decades have made the city an important clearing house for information about China.
Mighty Current churned out gossipy, thinly sourced titles that were popular with visitors from the mainland, where state-owned publishers face strict control and censorship, and where those engaging in public expressions of dissent risk being handed lengthy jail sentences.
The men went missing one after the other, only to turn up months later under the control of mainland Chinese authorities.
Four of the men have been released. One, Lam Wing-kee, said he was interrogated on sources for information used in the company's books and on its mainland Chinese customers. A fifth man is still detained.
The book fair, one of the biggest in Asia, has attracted tens of thousands of visitors since it kicked off on Wednesday. Last year, it drew more than one million visitors.
Its 640 exhibitors are featuring serious titles, mostly in Chinese, including volumes critical of China's Communist Party and President Xi Jinping, though they're outnumbered by lighter fare such as manga, self-help books and educational guides for students.
Jimmy Pang, the publisher of the small, independent press Subculture, said he saw no future for Hong Kong's political book industry.
The Mighty Current case involving the booksellers has sparked a "white terror", he said. "It's not just publishers, it's a problem for the whole industry," said Mr Pang. "Printing companies don't dare print them. Distributors aren't willing to distribute them." Many bookstores are controlled by mainland Chinese state-owned companies and refuse to stock them, he said.
Mr Pang's booth was displaying books that included works advocating greater autonomy for Hong Kong.
Another publisher, Bao Pu, described the outlook for the industry as "very gloomy".
Mr Bao's company, New Century Press, had trouble finding a printer willing to put out its latest title, a book about Qincheng Prison, a facility north of Beijing that has housed many prominent political prisoners. Mr Bao's father, Bao Tong, was a top aide to purged Communist Party leader Zhao Ziyang and was held for years in Qincheng.
Before the Mighty Current case, the "banned book" industry avoided the wider trend of falling sales because it was a market created by Chinese censorship.
"It was thriving for a while until they clamped down, until they made sure that everybody knows it's dangerous to buy these books. So when they do that it has a tremendous effect," Mr Bao said.
His Hong Kong-based company is best known for publishing a posthumous memoir on Zhao, who was deposed as premier for opposing the June 1989 military crackdown on pro-democracy protesters in Beijing's Tiananmen Square that left hundreds of people dead, if not more.
Hong Kong's academic publishers are feeling less pressure, and Chinese University Press launched a four-volume Collected Works of Zhao Ziyang, 1980-1989. The publisher said the compilation of nearly 500 reports, speeches and letters written by Zhao provides a detailed look at China's economic rise and insight into backroom dealings within the country's top leadership.
A Zhao family member provided the documents, said a person who worked on the book but refused to be identified because of the sensitivity of the project.
English-language books are not immune to the chill: Columnist Jason Ng said that, as he expected, his publisher's usual printer, based in the nearby mainland city of Shenzhen, refused to handle his Umbrellas in Bloom about Hong Kong's 2014 pro-democracy protests. But printers in Hong Kong also turned it down.
The printer that finally agreed to do the job would do so only if it wasn't named.
"That's sort of silly since the printer's name never appears on the book," Ng said. "I think that speaks to the general paranoia up and down the publishing food chain."