When the invite-only app Clubhouse was launched last April, it was envisaged as the online equivalent of Soho House: an exclusive space where the well-connected could gather.
But for a few days, it became something else: a tiny gap in Beijing's "great firewall", allowing millions in China a glimpse of an unfiltered, uncensored internet. A place where people could openly discuss issues like the treatment of the Uighur minority, the crackdown in Hong Kong, and relations with Taiwan, which Beijing considers a breakaway province.
"It's the first time I've logged on to the real internet in [the] Chinese language," a young woman from mainland China declared in one of the sessions.
It was short-lived: on Monday, the app some described as the Chinese version of the "Enlightenment Salon", went offline in mainland China - but not before the BBC listened in on a series of conversations which, just a week ago, would have been unimaginable.
'We are the same people'
When thousands of Mandarin speakers from mainland China and Taiwan joined a Clubhouse chatroom called "Everyone asks Everyone" last weekend, astute observers immediately sensed something unusual.
The conversation was no-holds-barred, ranging from the pros and cons of democracy in the Chinese-speaking world, and the possibility of unification of Taiwan with China, to occasional heart-warming personal stories.
"I was born and raised on the mainland, and I have never been abroad," a Chinese man said on Friday.
"We mainlanders say we are from the People's Republic of China; whereas in Taiwan you call your land the Republic of China. But why do we have to argue who this China belongs to? We should live peaceably with each other."
It is rare, because, amidst propaganda and tensions from both China and Taiwan in recent years, such sustained freewheeling discussions on a single digital platform are all but impossible usually.
Political content is normally filtered by China's sophisticated "great firewall" censorship system, with those daring to speak out on platforms like the micro-blogging site Weibo and messaging platform WeChat risking getting in trouble with authorities.
But there were no censors on Clubhouse, and speakers' confidence was apparently further buoyed by the fact the audio of users' chats in the app is not recorded, allowing some measure of privacy.
"I'm so delighted to hear these views," one woman from Taiwan chimed in during the conversation, which at some point attracted 5,000 participants.
"To be frank, there is propaganda on both sides. Why don't we try to understand each other a bit more; sympathise with each other and offer support when needed?"
The conversation was not all political, though. At times, people from both sides of the Taiwan Strait shared fond memories visiting each other's cities, while one mainlander pointed out that his favourite song from a Chinese indie rock band is in fact called About Taipei.
This was exactly the kind of conversation the group initiator Yaya Tsao was looking for on Friday.
"Despite the different rhetoric on both sides, there is still a diversity of views out there," Ms Tsao, 28, told the BBC from her home near Taipei.
After hours of moderating on Friday, she passed the responsibility on to a young mainland Chinese woman who calls herself GG.
"I'm very touched by these conversations," the finance professional said from her home in Shenzhen.
"I go to Hong Kong and Taiwan quite often for work, and I know how difficult it is to communicate on a single digital platform like this, let alone being rational and understanding of each other.
"I hope this kind of discussion can be the first step in helping both sides understand each other a bit more - after all, we are the same people with the same dreams and aspirations."
'Is there a concentration camp in Xinjiang?'
The discussions which were watched closest, however, were those on Xinjiang, the region where China is accused of locking up a million of Uighurs and other Muslim minorities in internment camps. Beijing insists they are "vocational schools" which combat "terrorism and religious extremism", and has accused the West of spreading lies and propaganda.
On Saturday, a chatroom named "Is there a concentration camp in Xinjiang?" hosted a 12-hour discussion between Uighurs and Han Chinese, China's majority ethnic group.
The Xinjiang chatroom's founding moderator Francis - not his real name - told the BBC the room title was chosen not to cast doubt on whether the camps truly exist, but to attract listeners with different views about China's Xinjiang policy.
"Many Han listeners, who used to have doubts about the authenticity of the camps, were touched by the Uighurs' personal stories and finally understood the scale of the atrocity. This may be the biggest achievement of the chatroom," said the 33-year-old Los Angeles-based filmmaker, who is ethnically Han Chinese.
One Han Chinese man said he had to stop driving as he was crying so much while listening to the discussion.
But there was also pushback, and trolls interrupted multiple times.
One Han Chinese woman defended China's Xinjiang policy by saying the US and Europe also took extreme anti-terrorism measures, asking: "Isn't education a good response?"
She noted some European countries have demanded immigrants learn their languages to assimilate. She was quickly reminded that Uighurs are not immigrants, but native to the Xinjiang region.
Some described her behaviour as "Hansplaining", which is when a Han person explains China's Xinjiang policy to Uighurs and other ethnic minorities in a condescending manner.
"The Hansplainers don't seem to care about how the policy affects the Uighur individuals," said UK-based Alex, not her real name.
The 27-year-old called on her fellow Han Chinese to educate themselves on what's happening in Xinjiang, rather than blame the victims.
Of course, Clubhouse's invite-only model, which saw some pay for access, as well as the fact it is only available on iPhones and iPads, means those who took part were likely overwhelmingly well-educated, affluent and urbanised Chinese elites.
Many pointed out that this setting may exacerbate the social media echo chamber, with popular Chinese blogger Ren Yi, who goes by the pen name Chairman Rabbit, noting that most mainland Chinese would never use Clubhouse.
"The content and trends will become increasingly one-sided," he wrote on Weibo, adding Clubhouse will turn into "another anti-China public opinion battleground".
But any chance for people on the mainland to sway the discussion has now gone. The app is offline - whether permanently, no one knows.
Yet Alex hopes the light she saw "shining through a crack" - however briefly - will be the first of many.
"Clubhouse is banned in China now, but as long as people have not lost their desire to communicate with each other, discussions will sprout up again on the next new platform."