The next morning we left in another Beijing jeep, as Aka Tenzin waved from the noodle shop where we had breakfasted. I sat in the back with Tsorsungchab and Tashintso, who held Lhamochab on her knee. Tsedup sat in the front next to the driver as he was prone to travel sickness. It wasn't him that we had to worry about this time, however; we had gone only fifty yards when Lhamochab was sick over his father's legs. Many Tibetans are not used to motorised vehicles, especially the nomads who traditionally prefer the horse if they have any distance to travel, but for these townsfolk the vibration of the engine, the smell of the petrol and the sense of claustrophobia were an unfamiliar hazard. Tsorsungchab did not drive because of the car crash that had damaged his eyesight. When he took off his dark glasses to wipe his weeping eye I saw the two-inch scar that ran beneath it. He told me, quite cheerily, that beer had caused the crash and ruined his sight. Now he didn't drink.

We had been five hours on the road and the weather was inclement. An all too familiar English grey had dissolved the sky, and I searched the smudged landscape through the steamy windows for signs of home: a curve of a mountain, the sweep of the grassland that fell from the Wild Yak range. I had missed my surrogate family and the tribe. The few days of drifting in Labrang had left me feeling displaced and I craved a sense of being rooted. I had never been much of a pioneer; too much a suburban girl at heart. However, now that his role as tour guide was officially over, Tsedup was desperate to return to Machu town to be reunited with his friends. He still hadn't seen many and was as keen to make contact with them as he had been to meet his family again.

First, though, we went to Tashintso's house. It transpired that she and Tsorsungchab also had a daughter, Tsepharchab, who must have been about eight and had been staying with her grandmother while they were in Labrang. She burst into tears as soon as she saw her parents and clung to them, in her yellow dress and pink socks, as we got out of the stuffy car. Their house was in the heart of the town, among the sprawl of concrete dwellings and courtyards divided by a grid of narrow alleyways and high walls. They unlocked their metal gate and we made our way into the courtyard, up the little path, past the tap -a much-coveted item – and round to the back of a shambles of outbuildings. In front of a red-brick inner courtyard was a gaily painted house with a conservatory of fashionable blue glass displaying potted plants. We sat at the table under the glass roof and Tashintso brought us some beer.

They had just finished building the house. It was simple, with a lounge area and two bedrooms all with wooden floors. In the front room sat two armchairs, a coffee table, wardrobe and dresser with silk flowers and a clock on it; otherwise the room was bare. The bedrooms contained only a bed with a neatly folded shiny pink quilt and a small cupboard. The house looked as if they had never set foot inside it.

The outbuilding crouching opposite in the yard was their real home and had been for years. It consisted of a parlour, with an electric cooker and glass-fronted cupboards, a bedroom with a small stove and television, and a back room for eating and for the children to sleep in. Its walls were decorated with newspaper but it was clear that Tashintso and Tsorsungchab had all the mod cons – except a fridge; that was the ultimate goal. If you had a fridge, you were someone. Tashintso's brother had a fridge; one day she would have one.

As we sat and drank our beer, Tsorsungchab busied himself. Something trilled shrilly from under the table and I was astonished to see that he had a mobile phone, which he answered proudly. I could see that he was fond of gadgetry – a land-line telephone sat on a small table in the corner, covered by a handkerchief to protect it from dust. Whether the calls were work-related or not was difficult to say. He looked important anyway, as he puffed on his cigarette and grunted loudly and repeatedly into the mouthpiece, 'Ah… Ah… Ah …' meaning 'what'. He seemed oblivious of anyone speaking to him, for the whats continued for some time before he settled into a rhythmic and repetitive boom of 'Oh… oh… oh.…' meaning 'yes'. Whoever was struggling to get a word in gave up after a short time and Tsorsungchab turned off the phone without saying goodbye. Amdowas don't say goodbye, they just say, 'Da de chi roi,' which means, 'OK, that's it.' I laughed eventually as his monosyllabic retorts seemed to be the only thing he was uttering and he laughed heartily back. 'Shermo, drink beer!' he cried, flicking ash into the green china ashtray. I was as much a source of humour to him as he was to me.

Tashintso busied herself with the children and unpacking. Lhamochab was turning circles on his tricycle in the yard, while his sister grizzled on the flower-bed wall. She had been abandoned and was not going to let her parents forget it. Her mother cooed comfortingly as she simultaneously swept the floor, put away the clothes and chatted animatedly with Tsedup and her husband.

'Tashintso is a policewoman,' Tsedup told me. I don't know why, but for some reason I found this difficult to believe. In my limited understanding of local authority and the machinations of this alien society, it seemed inconceivable that a Tibetan man could be a policeman, let alone a Tibetan woman, but I suppose this was Communist China, and women were just as likely as men to occupy positions of authority.

Tsedup pointed to a green uniform, which hung on a peg by the door. 'Look. That is her uniform.' She was indeed a woman of the law. Paranoia kicked in. Perhaps she was watching us. We should be careful. As if he was reading my mind, Tsedup explained, 'Tashintso is going to help us. She says she will arrange for us to meet the local police sergeant soon. He will want to have an interview with me.' Perhaps it would be a good thing to have a friend in the police station after all, but the thought of an interview made me shudder.

The next day as I was brushing my teeth in a tin bowl in the sunny yard a familiar figure appeared. He wandered around the edge of the outbuilding and said, 'Hello, Kate.'

I was so shocked to hear a Tibetan speaking English that I nearly choked. He looked older, but it was unmistakably Tsempel. He had been a great friend of Tsedup's in India when we had first met, but had returned to Tibet soon after I left for England. I had not seen him for five years. His front teeth were chipped now from splitting melon seeds and around his eyes were deep lines I didn't remember. He was thin and slightly stooping, with an apologetic air, and he spoke calmly and quietly in a low, husky voice.

'Arro, Tsempel. Cho demo?' I asked, as we shook hands firmly.

He replied in English again, 'I'm happy to see you.'

I ran to the bedroom to wake Tsedup and he sprang out of bed. The two embraced warmly in a blurt of excited dialect, and it struck me, as I looked at them together, how much time had passed. It seemed now almost as if they were from two different worlds. Except, as with all the other reunions I had witnessed, there was an immediate connection between them. It didn't need to be spoken; they were like brothers. Whatever they had experienced, whichever path they had chosen, they were essentially the same. They were 'Amdo boys', and that, I had learnt, was a phenomenon unto itself.

The clarity of the concept is derived from the exiled community in India, which is split into the three regions of Tibet: Kham, Amdo and the Tibetan Autonomous Region, (TAR) with those who have been born in exile. For the most part they live harmoniously, but certain hostilities and prejudices exist. For a start they all speak different dialects. The majority, who are from the TAR or who were born in India, do not understand the regional dialects of Amdo and Kham, and it is the responsibility of the latter to learn the dialect spoken by the TAR. Meanwhile the Amdowas and the Khampas always stick together in their regional groups, like small tribes. They are from farther away and as most of them have left their families behind, the young men are freer than the others to express themselves and take advantage of their new-found freedom. When I met Tsedup, he shared a tiny cell-like room with seven other Amdo boys where they baked bread to sell on the street. They relied on each other for everything and an even greater bond existed between them than when they were in Tibet. The ' Lhasa boys' are often afraid of the Amdowas who, like their Khampa neighbours, have a reputation for brutality in fights. The Amdowas are often made to feel coarse and crude by the older Lhasa Tibetans especially, being 'countryfolk'. But they are also revered generally for their dominance of Tibetan literature and music, of which Amdo is the heartland.