This year at the time of China’s Golden Week holiday, Hong Kong’s busy streets and major malls seemed to be taken back by its residents - the scene of Chinese mainland tourists crowding Tsim Sha Tsui streets with a handful of shopping bags and taking skyline photos at the Avenue of Stars is gone.

According to the Immigration Department of the Hong Kong Special Administrative Region, 433 visitors from the mainland entered Hong Kong in the first three days of Golden Week. Compared with 417,671 in the same period of last year, the number dropped by 99.8%.

Hong Kong started seeing a sharp plunge of mainland tourists since protests began last year. The movement that engulfed the city in 2019 was triggered by a murder. In February 2018— a 19-year-old Hong Kong man Chan Tong-kai allegedly murdered his pregnant girlfriend Poon Hiu-wing on their vacation in Taiwan. Chan fled back to Hong Kong, but he could not be sent to Taiwan to face criminal charges because of the lack of an extradition agreement between the two jurisdictions.

The extradition bill - which was intended to “plug legal loopholes” sparked great controversy. People take to the street to protest against the proposed bill, which they fear will jeopardise the city's judicial independence.

What started as peaceful anti-government protests escalated into a violent clash with the police. The protestors began to smash subway stations and set up roadblocks, which made getting around the city difficult; banks and shops were targeted and had to be shuttered. The months of turmoil caused huge disruption to businesses and daily life scared off tourists. Mainland tourists’ arrivals fell more 56.2 per cent during the 2019 Golden Week from the same period the previous year.

The bill was officially withdrawn, but the unrest did not cease. It also came at a timing when the U.S. is readjusting its China policy. As a link amid the U.S-China trade war, Hong Kong was threatened by the U.S. to be stripped of its special economic and trade status by revising the United States-Hong Kong Policy Act of 1992, which inflicted a great economic toll on the economy.

Then came the Covid-19 pandemic to add another major blow. Hong Kong had its first cases on Jan. 22, and the situation soon evolved as overseas residents and students started returning to the city. In February, the Hong Kong Government already closed 11 out of 13 border crossings and starting on March 25, non-Hong Kong residents coming from mainland China and abroad were subject to a 14- day compulsory quarantine, a move that directly led to slump of visitors.

On Sept. 1, China sent its health workers to help conduct a free mass testing for Hong Kong citizens. However, the initiative was encountered with skepticism and limited response - Pro-democracy campaigners swirl fears that DNA samples will be sent to Beijing and called on the public to boycott the programme. It mirrors the distrust and tensions following more than a year of social turmoil and the pass of national security law.

The proposal of national security law, which criminalises four types of acts: secession, subversion, terrorist activities, and collusion with a foreign country or with external elements to endanger national security, coincides with this timing of the city’s non-stop unrest in a hope to return stability to Hong Kong. It consequently makes it easier to punish the protestors - the protests that decreased its momentum amid the pandemic evolved into a wider pro-democracy and anti-China movement.

The US in response, halted its extradition treaty with Hong Kong and terminated its preferential trade and diplomatic status. The Hong Kong government responded saying it "strongly objects to and deplores” the US action, which is widely seen as “a move to create troubles in China-US relationship, using Hong Kong as a pawn.”

At the beginning of October, when Chinese people crowded tourist spots again as the pandemic was largely under control, Hong Kong was still experiencing a third wave of infections. The reopening of borders between mainland China and Hong Kong is further delayed and remains uncertain as to how soon it will happen.

Who would have thought that a murder case involving a citizen upended life of a whole city? One theory can take credit for it - the “butterfly effect”. Originally proposed by a meteorologist named Edward Lorenz, the phenomenon suggests that a massive storm might have its roots in the flapping of a tiny butterfly's wings from faraway. The theory has proven to be very useful in social events - a tiny mechanism may trigger a set of events that will ultimately culminate a “revolution” after developing a period.

Underlying this, however, is the complexity of many issues multiplied together: Hong Kong people’s distrust of their leader and Beijing central government; the China-US relationship and the special relationship between China and Hong Kong - despite their close economic ties, the political gap remain entrenched under “One China, Two systems”; Hong Kong’s status as a global financial and business centre also decides that the rest of the world holds tremendous interests in it.

There may be an ultimate solution that can stop Hong Kong from further down the slope and bring back its peace and business vitality, at a moment of crisis like this, what we can do at least is hang on to the hope.