In the lingering darkness before dawn, more than 100 plain-clothes police marched down the steps of Xidan, one of Beijing's most important shopping streets, to wait for trading to begin on the pavements and narrow alleys off the main street.
Their interest? New and second-hand bicycles that sell for the lowest prices in Beijing's biggest black market. Just before half 7.30am, the police made their first arrest, of a 36-year-old farmer from Henan province named Wang Xiucheng, who arrived with eight green ladies bicycles stolen from an underpass close to the Labour Building.
By the end of the afternoon, they had interrogated 26 people, detained 13 and confiscated 30 stolen bicycles. 'We will go on doing this until we destroy the market,' declared the officer leading the operation. 'It is our unshakeable duty.' Two days later, a visitor went to Xidan in search of a cheap bicycle. 'Not this week,' said a man with a big smile on his face. 'Come back next week. Business will resume then. With so much attention from the police, we have to lie low this week. It comes and goes. When it goes, things will get back to normal.' His advice was to go down the alleys off the main streets, out of the gaze of the public and the police. Daily turnover, he said, was more than 100 bicycles for 100 to 200 yuan (HK$93 to $186), a third or less of the price in regular shops, with customers mostly students and migrant workers.
'What market?' said a security man outside a bank. 'It closed months ago. You should go elsewhere if you want a cheap bicycle.' That is the official answer.
The black market began about 10 years ago near a state shop set up in the 1960s to sell second-hand bicycles. The market's prosperity forced the shop to close. The thieves mainly operate at night, taking their pick from thousands of bicycles parked outside, using keys or steel clippers.
The only catch is that the bicycles have no licence plate, which could lead to awkward questions from your neighbourhood policeman or the old lady with the red arm band on the street committee.
In 1994, people reported the theft of 63,326 bicycles in Beijing, accounting for five per cent of registered crimes. After that, the police gave up counting, saying that they have more important things to do.
For 64-year-old Wang Guomin, working at an electronics shop in Xidan, the success of the black market is a sad commentary on what has happened to his country.
'My bicycle is rusting and not worth much but I dare not leave it outside. I have to park it inside the single room where I live with my wife, my kitchen stove and everything else,' he said.
'Public morality and social order has deteriorated and people care only about money now. In the 1950s we had a strong sense of public order and reported criminals to the police. But not now.' The thefts are also a sign of increasing unemployment. People have no work and no income, He said. This is a common sentiment among older people who remember with fondness a feeling of common purpose and equality in the early 1950s. For them, Deng Xiaoping's reforms have led to unimagined wealth but which is unevenly divided, resulting in waste and extravagance by the rich and bitterness and crime among the poor.
'I am a Catholic,' said Mr Wang. 'When I die, I will be judged on the good and bad deeds in my life and go to heaven or hell. But few people believe in that. They exist just for this life. They think: 'why not make as much money as you can and spend it all before you turn to dust?'.'