Over the brow of the first hill 15 km west of Pristina, the Kosovan capital disappeared from the rear-view mirror. At precisely the same moment three men with semi-automatic weapons appeared in front of the car, having stirred themselves from a shaded position under a tree.
Here, Serb law ends and the rules are set by the largely scruffy unshaven bunch of men known as the Kosovo Liberation Army. Typical of many such conflicts, the guerrillas control high ground, the authorities the roads below.
They said we could not pass, then that we might be able to pass. They asked for passports and for the vehicle registration papers.
There was much grave transcription of details onto pieces of paper. Finally, we could proceed, but we must bring one of them - a man in his late forties with a droopy moustache and a gun - with us.
We set off, me, the 19-year-old Pristina law student who was acting as a translator and the man with the gun. This man lectured the law student about the smugness of Pristina as we bumped at 5 m.p.h along the dirty mountain track.
"You people in Pristina are still asleep," he said, "and it will not be us who will wake you up, it will be the Serbs. They cannot get at us in the mountains, they can only get at you, and they will."
He was repeating the rumour doing the rounds of Pristina that there would be a major atrocity soon in the town itself.
Yesterday we were trying to get to the mountain village of Vasileve, to which the population of Glocovac down below fled two weeks ago. Serbian forces had attacked villages near Glocovac - they said they attack only "terrorists" but Kosovars say they can't find the KLA so they kill civilians instead. Glocovac, we had heard, was now a ghost town.
A jeep containing four armed men came towards us as we dropped over another hill. As we stopped to allow each other pass the driver of the jeep asked for documents, passports, vehicle papers before allowing us proceed. These, too, were the KLA, driving about freely just 20 km west of the capital of an internal province of Serbia. There is no doubt that the KLA controls this area, and that it would be very difficult indeed to clear them out of this inaccessible, rugged territory.
Half an hour into the mountains, a dozen men guarded the final checkpoint outside Vasileve. Unusually, two of these had uniforms - one even had the KLA insignia (UCK in Albanian) - on his sleeve. The KLA, just two months ago depicted as a bunch of peasants with a few rifles, is slowly becoming larger and more professional.
And, as in other such situations, the guerrillas have invented rules and bureaucracy. The leader of the dozen men at the checkpoint put his hand firmly on his heart as he leaned in the car window and made a speech slowly, clause by clause, to ensure the law student could translate thoroughly.
"I hope you will not misunderstand us," he began. "We appreciate that you have come here and taken the trouble to travel so far on that very bad road. But we can't allow you go any further because we have rules now which are meant to be respected."
These rules had arisen since the KLA appointed a spokesman. Now we must go to see him first - over an hour away - if we wanted permission to travel further. But of course until we had permission, we were liable to be stopped at KLA checkpoints elsewhere, and so we might not be able to get to where the spokesman was based.
The commander was very sorry, he insisted. "We have great respect for the Irish," he added helpfully.
Half an hour later we turned towards Glocovac, the town deserted by civilians in terror of Serb forces.
Three Serb armoured personnel carriers passed at speed in the opposite direction towards Pristina, helmeted men in the gun turrets at the ready.
Twenty minutes later we came to Komoran, the last Serb checkpoint before Glocovac. A policeman scrutinised our passports and warned us of "terrorists" who had roadblocks in Glocovac. He could guarantee our safety in Serb held territory, he said, but not in Glocovac.
There were no terrorists in Glocovac. There was nobody there at all. Supermarkets, cafeterias and other shops were closed and deserted. Rows of houses and four blocks of flats stood empty and silent. You can see for about a mile in each direction from the centre of town. The people who fled two weeks ago were very afraid indeed, as was a man at the petrol station outside town. Two men and a woman were hosing down the forecourt, mowing the grass verge and sweeping around the filling station.
Asked why there was nobody in town, one man said he did not know, he had never been to Glocovac. The town was visible just down the road. He continued sweeping.
The other man denied that the town was deserted. Indeed, later we saw two elderly people cutting long grass around their house with scythes. Back at the Serb checkpoint the same Serb policeman approached the car with his gun. He told me to open the boot for his colleague as he leaned in the window, looking at my translator. He saw a hotel room key in the glove compartment and asked her what hotel she was staying in, and what room number. She said the key was mine, and that she lived in an apartment in Pristina.
"Where is that?" he asked. "We might come and visit you." She momentarily lost her feigned politeness. "No thank you," she said sharply, looking up straight at him.
He saw I had noticed the change of tone. "I'm sorry if I was not polite," he said, grinning and detaching himself from the car. "Goodbye, pretty. Hope to see you soon."
As we drove back to Pristina and she translated the conversation she sounded angry, but said she had not really been frightened. "I did not think he was going to rape me. There were people around."
She went on to tell the story of the unconfirmed rapes in Decani, elsewhere in Kosovo, of two Albanian sisters, aged 13 and 14, who then committed suicide, she said.
It is easy for Kosovo Albanians to be frightened by Serb police and soldiers, especially when - as in Glocovac two weeks ago - there are no outsiders around.