In a ramshackle group of whitewashed buildings hidden behind the mortuary at Beijing's You An hospital, Doctor Zhang and his small group of nurses run one of China's handful of Aids clinics.
There are growing signs that HIV infection rates in China are increasingly rapidly, and many specialists are now warning that the country is on the verge of a major epidemic.
Some predict there could be 10 million people infected by the HIV virus within the next five years.
But Aids sufferers in China face widespread prejudice, and government efforts to educate the public about the dangers of HIV have barely begun.
In a ramshackle group of whitewashed buildings hidden behind the mortuary at Beijing's You An hospital, Doctor Zhang and his small group of nurses run one of China's handful of Aids clinics.
The clinic has beds for only six patients. In the sweltering summer heat, the tiny unairconditioned rooms are suffocating; and yet, for China's Aids sufferers, this is a haven of care and a refuge from a society that would prefer to believe they did not exist.
The woman is painfully thin, her arms covered in the tell-tale lesions of Aids.
She can accept that she is dying, she tells me - what hurts most is the prejudice of other people.
"This is not any ordinary type of prejudice, it's much worse," she says.
"If anyone finds out, they won't dare to come near me. I can't even tell my friends and relatives; and its not just me - if they find out, people will look down on my whole family."
Discrimination
That prejudice, Doctor Zhang says, is hurting China's ability to deal with a growing Aids crisis.
"In the whole of China, there are perhaps only five doctors like me working on HIV," he says.
"I even find myself discriminated against. Even in this hospital, people don't understand - they think the kind of work I do is terrifying."
Aids is a problem China can no longer afford to ignore.
This year, the estimated number of HIV carriers in China will pass one million. Some doctors - call them pessimistic or realistic - reckon in five years, the number will be 10 million.
Sex centre
Today in China, there may be as many as 10 million women working in the sex industry. Yet few know anything about HIV or how to protect themselves against it.
Last week, China's first sex education centre opened its doors to teenagers in Beijing.
Sex specialists like Professor Xu Tianmin of Beijing University used the opportunity to make a blunt wake-up call.
"We cannot delay any longer," he says. "We cannot continue to ignore the reality of the situation.
"People say in China that you can do anything as long as you don't tell anyone about it.
"But all that means is no one wants to admit the reality of what's going on. This is very dangerous."
Condoms
But so far, this is the only sex education centre in the whole of China.
Even in big cities like Beijing and Shanghai, more than 50% of high school students still receive no sex education whatsoever.
Attempts to use the mass media have also run up against a bizarre official prudishness.
A television ad promoting the use of condoms was taken off air after just two days because the authorities said it violated a ban on advertising sexual products.
Aids is burrowing its way into China's population.
A lethal combination of ignorance and prejudice means virtually nothing is being done to stop it.