Donating organs to strangers will soon be legal in Britain. Here, Slavenka Drakulic tells how she met - and fought to understand - the 'angel' who gave her a new kidney

There she was, entering the room at the hospital in Providence, Rhode Island, in a wheelchair pushed by a nurse. For days now I had been consumed by curiosity about her. I wanted to see what kind of person possessed such generosity. Ever since I had been told that I was having the transplant surgery, I had tried to imagine her face. When I arrived on the day of the operation, I wondered: would I recognise her? Would she look special? I wanted to meet her, but would she want to meet me? She had no obligations towards me; she could have said no. Why should she meet me? She wanted to help someone who needed a kidney, not me in particular.

Now I was finally seeing her in front of me, a good-looking young woman with a fine-boned pale face, intense green eyes and short blonde hair. She was dressed in a plain grey sweatshirt and blue sweatpants. Slightly bent to the left, she kept her hand on the incision. Even though she was sitting down I could tell that she was tall and slim. Here comes my own "angel", I thought.

"Christine Swenson," she said simply, shaking my hand firmly. She looked at me. The room was full of people - her mother, her stepfather, a nurse - but in that moment I saw only her. Facing Christine was the strangest experience in my life. I do not know who smiled first, maybe we smiled at the same time. A delicate, joyful moment when we realised we were no longer strangers, that we liked each other.

For an awkward moment we were all silent. Absurd thoughts were running through my head about how I looked to them and if they would like me. I desperately wanted all three of them to feel good about the person who got her gift. I must have been a frightful sight: my hair was greasy, my face swollen from medicine, and there were tubes sticking out of my body. The room smelt of disinfectant, sweat and medicines - hardly a fitting stage for a miracle of new life.

I was overwhelmed with feelings of gratitude towards Christine, but also of tenderness. Incapable of finding any other appropriate words for her, I just said: "Thank you, thank you for saving my life." Christine looked at me, and I saw that she blushed. She must have thought I was being too theatrical. She might have improved my life, but saving it?

I probably should have died 26 years ago, when I was diagnosed with a polycystic kidney disease (PKD) and told I needed a dialysis right away. I was 30 and living in Zagreb, in the former Yugoslavia. But the country was poor, and there were not enough machines for all the patients who needed them.

I learnt that four out of five people in need in my homeland did not get their place on the machines. They died. The reason for this catastrophic situation was simple - very few transplant operations were performed. I recently met two more people from the group of 12 patients in my shift who, besides me, survived the past 20 years because they, too, had had a transplant. Everybody else has passed away. That is 45 out of 48 patients.

After six years on dialysis, I had my first (cadaveric) kidney transplant in Boston in 1986. It prolonged my life for almost 15 years. But at the end of 2000, my kidney decided to give up. I was back to dialysis.

I knew nothing about Christine, nor did she know anything about me. Quickly, almost breathlessly, as if this would be my only chance to win her over, I told her about my 25 years struggling to survive on haemodialysis, before my first transplant, then again on dialysis. I guess I wanted to prove to her somehow that I deserved her kidney, that I had suffered enough all these years. It was as if she had been the judge who decided it was to be me.

I wanted to know so much about Christine, about her family - she told me she had a husband and two children - and how she had decided to become a donor. Above all, I wanted to know why she had made the decision.

The story of my second transplant really begins on 11 July 2004. On that day the local newspaper, The Providence Sunday Journal, published a long report about a 21-year-old altruistic donor called Kristy Olivet. She wanted to donate her kidney and went to the Rhode Island Hospital because she had heard that its transplant surgery department had such a programme.

Her kidney, doctors decided, fitted a 65-year-old man, Albert Raposa. After reading that report in the paper, five women and two men volunteered to donate their kidneys in the same hospital. I was amazed that one single story could have had such an effect. For a moment I was even proud of being a journalist, in spite of the cynicism we journalists often develop.

Christine was one of these five women. When she read the article she thought: "I could save someone's life." "Just like that?" I asked her, still incredulous, even though her kidney was already in my body. She was silent for a moment. Her answer was disarming: "Yes, just like that," she said, as if there was no need for an explanation of such an act.

But I needed to understand why she did it, because for me the comprehension of her act was a part of accepting her gift.

I asked her again the next time we met. She had invited me to her house in a suburb of Providence. We sat in the dining room, not yet friends because we knew so little of each other, but there we were face to face, donor and recipient. That's who I was to her, a recipient of her kidney. As I sat there, I touched my belly. I did not feel the kidney itself, just the incision, still fresh but no longer painful. Ten days had passed since the surgery. It was a very strange feeling to sit opposite a person, a part of whom is in you. Was it her kidney? Or was it mine now?

Christine's children, Sean, 11, and Tori, eight, were at school, her husband was at work. "Did you tell them about the surgery? Were they afraid?" I asked her. "My kids are my life. I would never do something that would leave them without a mother," she said. "I told them: 'Your mom is healthy. I am helping someone who lives with the help of a machine.'

"I saw that they were a bit worried, but in their school classes they said they were proud of me. Tori said, just the other day, that she, too, would like to donate a kidney when she turns 18!"

Then I asked her: "Christine, what if one of your kids should one day need a kidney?"

"I would hope somebody would come forward to help, as I did," Christine said. She said it as if nothing could shake her confidence in human beings. Christine was teaching me optimism: without using these words, she taught me that people are good, that I should never doubt it.

"But how about yourself? Were you afraid of the surgery?" She brushed off the suggestion with a wave of her hand. "No, no, I did not even consider any complications. I am very healthy. No. I was not afraid."

Talking to friends back home, I realised that to them the news about my altruistic donor was no less amazing. They, too, demanded an explanation. Why did Christine do it? Is she perhaps religious? Did she do it for money? As if altruism itself is not comprehensible enough, not so self-evident a motivation. No doubt there is something shocking about a stranger giving you her kidney as a gift, because this is not what strangers normally do.

When I first saw her, I thought of her as an "angel". There, in Christine's home, I was getting angry with myself for succumbing to a cliché. She was not an angel. The beauty of her act lay in the fact that she was a perfectly ordinary person capable of such sublime altruism, kindness, generosity, largesse, goodness and excellence. It is difficult to give a name to what she has done; how much easier it is to name and describe the other, darker side of the human soul.

By labelling such people as extraordinary, we mean that we, the ordinary ones, would not be able to be either that generous or that monstrous. This might be our way of dealing with the banality of evil, but also with the banality of good. Goodness belittles you - I felt it so strongly when Christine came to my room as an ordinary person, and a stranger at that, who had committed an act of altruism.

It makes you insecure. You are not sure if you would be capable of the same thing, and you hate yourself. You see yourself as selfish, egocentric - and that is acceptable but only as long as you believe it is how normal people are. But human beings can be good and evil - not what we expect to learn about ourselves.

Again I touched my incision. Her kidney was inside me, and I could not but ask myself: what are we, Christine and I, to each other now? Are we related in some strange way? Has the kidney transplant turned us into something close to relatives? With her kidney in me, I am flesh of her flesh. We are relatives, although nobody knows what kind. And Christine didn't seem confused about how to define our relationship. "I gave a kidney and gained a sister," she stated later.

I, however, got more than a kidney and a younger sister. I got faith in ordinary goodness. I got a chance to be good to others. Because of Christine I got into a situation where I could focus less on my own needs and my worries - and that is a big gain.

Slavenka Drakulic is the author of They Would Never Hurt a Fly: War Criminals on Trial in the Hague, Abacus/Little, Brown £8.99

The new rules on 'living' organ donation

* People in the UK will be able to donate organs to strangers from September. Giving in this way is already legal in the United States.

* The first "stranger" donations are likely to be of kidneys but they may later include livers and other organs. Currently, living donations, which number 500 a year, are only permitted between people related genetically or emotionally in the UK.

* The change in the law is expected to boost the number of transplants from living donors, saving between 40 and 50 extra lives a year, according to the Human Tissue Authority.

* There is a shortage of organs for transplant and a long waiting list. There were 2,180 transplants performed last year and 6,689 are waiting for an organ to become available.

* It is possible to live a normal life with one kidney. The liver regenerates so it is also possible to donate a portion. A portion of the lung can also be given away.

* Before undergoing surgery, donors will be tested to check that they are fit, and that their kidneys or other organs are working well. They will be checked to see that their kidney is a good match - though matching blood groups is usually sufficient.

* A statistical quirk of this assessment is that because it selects the healthiest people, those who pass it necessarily have above-average life expectancy. Their chances of suffering kidney failure are thus lower, even after one kidney has been removed.

* Altruistic donors (giving to strangers) will be psychiatrically assessed. The Human Tissue Authority will ensure there was no coercion or cash incentive involved.