As I write this we are six and a half hours into a 20-hour bus journey from Bariloche to Mendoza. We got on the road at 1.30pm and it’s now 8pm. We are in a town called Neuquen, where for some inexplicable reason there are two bus stations within a kilometre of each other. We stopped at each of them for fifteen minutes, and now we are pulled into the yard of the bus company, presumably to get diesel. This will be the last great land journey of our time here – our final step is to fly from Mendoza back to Buenos Aires on the 22nd, then head home to Ireland on the 24th, arriving on the 25th.

The time has passed easily so far, a day made up of large numbers of small moments. This morning we went out to buy food for the journey in a supermarket in Bariloche, learning our lesson from the last long trip, so we have bread and ham and cheese within easy reach. We got a taxi from the hostel to the bus station, bought the bus tickets, and had lunch. We met the Korean girl from yesterday there by chance; but I have not yet mentioned her as I have jumped out of chronological order. We’ll get back to that in due course.

The bus pulled out dead on time and for the first hour or two we passed through the lake-strewn landscape around Bariloche. In the distance were snow-topped mountains, their peaks outlined bright against the sky, and closer were smaller hills of rocks and stones and sand. Some of the lakes are huge, several miles long and wide, running up against the base of the nearest hills. The water is a deep turquoise, the colour caused by the sediment washed in from the mountain rivers. It goes on and on in endless beauty. But as the miles went by the glory of it faded gently away. The lakes became rarer, the mountains on the horizon disappeared, the hills shifted from verdure to desert, and we were back in the great nothing that makes up a much larger part of Argentina than I had ever known before I got here.

The stops seem to be roughly three hours apart, aside from the current run through Neuquen where progress has slowed to the pace of erosion. A petrol station on the side of the road or a two-street town may not be the kinds of things that I would generally look forward to, but they assume a new significance when movement in between is so constricted. The bus pulls up and they make an announcement on the PA system, and generally I can catch the number of minutes we have before we leave again, and generally that number is 15. Usually before they pull out they beep the horn, but not always; the odd solo traveller must occasionally get left behind.

Activities on the stops vary. I think I have already mentioned the dogs – if there are any around they are the primary source of fun, but really anything is up for consideration. At the last one the most notable attraction was a line of ants which were busy carrying small pieces of leaves and twigs and things that were proportionally gigantic to a distant destination. I was able to follow the line to scrub grass at edge of the petrol station, and paced it out on the way back at about 25 metres. If an ant is one centimetre long and we make a very rough approximation on body length, this is the equivalent of me carrying something about 5km, where ‘something’ is a telephone pole or a slab of construction concrete. And these are the kinds of things I think about when there is nothing in particular to think about.

Not long after we got on the road they put on a movie, Salt, with Angelia Jolie, which I had already seen. It was no more intelligent or less entertaining the second time around. Then there was a stop, then a second movie, a Beautiful Mind. I liked it better than when I last saw it, which I think was in the cinema. Oddly as it was about to reach its climax in the Nobel acceptance speech, they chose to make a long and impenetrable (to me) announcement on the PA system about our future movements, drowning out the film audio. The gist of it must have been that we were going to be in this town for a quite a while, though at this precise moment we are finally underway. It has become completely dark since we got here. And they have started showing the Hangover, which I have also seen, and it as witless and low-denominator as when I last saw it. There are occasional moments of humour in it, I will admit, as there must be occasional patches of nutrition in the collective excrescence of a civilisation.

The seats in the bus are reasonably comfortable and they recline a decent amount, but we are not exactly anticipating a restful night’s sleep. It’s not as nice as the buses Katie and I took in Peru, though on the other hand it’s a step up from the mini-bus from Rio Gallegos. Downstairs in the nicer seats somewhere is our Korean friend. Some of the seats are empty. To our right is a man who coughs a lot, and when he does it is a lurching wet sound that hints at a serious illness. Maybe Ebola. He has a coffee cup in the holder on front of him that he spits into from time to time, and it makes my face contort somewhat when I think about it. He is clearly not in good health, the poor man.

Yesterday we did the rafting, as already mentioned. The bus picked us up early in the morning and it was about two hours to the first stop, driving through the lakes we saw again today. We had a very light breakfast and picked up the raft on a trailer, then went to where we would be starting off. We got a detailed safety lecture on what we should do in the event of falling in the river, which was rather different to the only other time I was ever rafting, in India, where it was added as an afterthought that if you found yourself in the drink you should probably float feet-first to avoid bashing your head on the rocks. This time around they showed us the safe position to float (keep your feet up as high as you can to try and float over as many rocks as possible) and explained the commands we would get with regard to when to row and when to stop.

There were eight tourists in total plus the guy in charge at the back of the raft. When he shouted ‘forward’ everyone paddled forward, which in the event was the one we mostly got right. ‘Right back’ meant that the people on the right side paddled backwards, but the implied unspoken part was that the left-side people needed to paddle forward. The same was true in reverse for ‘left forward’ – both of these were for turning the raft either way. ‘Back’ was at least pretty straightforward. Confusing things though was that ‘right’ or ‘left’ without an accompanying ‘back’ meant that that people should dive across the craft to change the weight balance if the raft was tipping. ‘Right’ meant the people on the left should dive into the spaces between the people on the right, and ‘left’ the opposite.

All of that reasonably clear, we set off. There were ten rapids into total. The first was very gentle and we bumped through it. On the second, though, we managed to get the raft stuck on a rock in the centre of the rapid, hanging at a slight left-to-right angle. There were five Americans on the raft, the two of us, and the Korean girl. Some of the American girls were rather freaked out by this turn of events, as to try and free it we needed everyone to get as close to the front of the raft as possible and jerk forward in unison to try and shake it free. All the while the noisy swells of the rapids were just to our left and right, and the angle of inclination increased as we inched the boat forward, so it was indeed somewhat precarious. But after two minutes or so we were on the water again.

Other rapids were much smoother. One was so small we went through it trying to stand up, which is about as hard as you would expect it to be. The best of the rapids was one in which the raft went hard down into a wave I would guess was a bit over a metre high, and the wave broke over the raft. Mike and I were in the two front positions and caught it right in the face. It was cold and invigorating. Following our progress on the banks of the river was a photographer with a big zoom lens, and she took pictures of us in some of the best places. She got some great shots of the raft almost hidden under the foam of the breaking wave.

In winter the river rises six metres above the level we saw it at, and in most places the banks were steep and the tops of them were high above our heads. You could see the waterline in the colour of moss on the rocks. Some of the rapids disappear entirely in winter as there is so much water above them. At one place we passed between sheer rocks walls and came into a sort of curved enclosure where the water gathers and swirls when the river is high. Traced all the way up along the rock were curves that had been carved by the rotation of the water, and though we passed through for only a few moments I loved it; it seemed such an smacking illustration of the slow power of water on a scale of time so long it might as well be endless.

About half way through the journey we passed a small waterfall and directed the raft over to it. I lay back in the boat put my head under the falling water and drank from it, which is something I suspect will be a rare occurrence in my life. It was cold and strong and wonderful.

The bus dropped us back about seven and we had a quiet evening. We went for dinner in a place that was recommended in the guidebook. I’ve had a very hit and miss time with the Lonely Planet recommendations, which tend to apply to places that were active in 2008 when it was written but have since closed down or changed name. This was one of the latter group, operating under a different title, but it was a lovely place. We had lamb that was tender and flavoursome and I had a glass of the house red wine, which was much better than most of the wines I have ever paid for from a menu. We went to bed early, but yet another night escaped me without the rest I would have hoped for.

That brings us to today and to the bus, and as I write these closing lines the Hangover is finishing. I like the end of it better than the beginning, I have to say. It’s 9.35pm so through the window there is only darkness split by the lights of passing cars. Probably when the film is over they will not show another and everyone will settle down for the night as far as such a thing is possible, and many of the remaining hours will hopefully drift by peacefully. It’s strange to be on the road for eight hours and not yet be even half way there.