Toward the end of September, almost three weeks after arriving at our idyllic base camp a short distance above the village of Koyo, the unmissable bulk of Koyo Zom’s north side couldn’t be avoided any longer. The time had come to attempt the 6,877-meter peak. Although we had originally intended to attempt the right-hand side of the face as a party of five (probably two teams climbing alongside each other), we were coming round to the idea of one team trying the right skyline (the northwest face) and one trying the left-hand skyline (the northeast buttress). As circumstances dictated, Tom Livingstone and Ally Swinton decided to try the right-hand line and John Crook, Uisdean Hawthorn and myself the left line. [Click here for the AAJ report about the Livingstone-Swinton climb on the northeast face.]

All five of us spent the night of September 23 at our advanced base camp (4,500m), and early the next day, John, Uisdean, and I set off for the northeast buttress. We traversed the upper Koyo Glacier, which at that point was a huge, complicated, messy icefall. We crossed a bergschrund and climbed the initial face to a col (ca 5,400m) in about 10 pitches of moderately difficult but very tiring sugar snow on black ice, with some mixed sections. The sugary snow on black ice was to be a theme of the next few days!
 
At the col, we made a platform big enough for our three-man bivy tent and enjoyed a very comfortable night. The next day we stayed on the crest of the northeast buttress and climbed around six pitches of moderate but time-consuming mixed ground, again consisting largely of exhausting powder on black ice. Upon reaching a rock pinnacle that we had identified from base camp as a potentially tricky obstacle, we were forced to do a 60m rappel down the east side of the buttress to bypass it. We decided to bivy again shortly after the rappel, as there was a rocky ledge we could sculpt into a relatively comfortable platform, and the next section looked like several pitches of steep, brittle serac ice, which we didn’t want to climb into the night.
     
The next morning, our third on the route, we traversed a couloir and then climbed the serac ice in about six pitches to a snowy spur. We continued for a further three pitches of the nasty snow on ice to reach a point where we could construct another semi-sitting bivy. We carried on the next morning, becoming increasingly frustrated by the exhausting powder-on-ice combination. An enjoyable but loose mixed section, followed by an elegant icy gully, brought us to a point only 40 vertical meters below the horizontal summit ridge, after about eight pitches in all. However, as John was leading the last stretch to the ridge, we all decided we would bail down to the Pelchus Glacier, east of the mountain.
 
This decision was due to an accumulation of factors. First, the last forecast we had received stated that a storm would be arriving that evening and lasting for the foreseeable future. Unfortunately, our satellite phone hadn’t worked for four days (since leaving ABC), so we hadn’t received the message saying the storm had been pushed back. We also had taken two days longer than expected to climb the buttress. The final straw, which turned us around where we did, rather than finishing the last pitch and taking stock (John was 30 meters out on the last lead to the horizontal ridge when we made the call) was that Uisdean was having worrying chest pains that seemed to be getting worse. We spent the night on the Pelchus Glacier and then returned to base camp six days after leaving.
 
Despite being a magnificent line, the route we attempted had annoying, time-consuming climbing and a convoluted path. I personally was the weakest I have ever felt on a big mountain, by quite some margin. This was easily attributed to spending the 10 or so days prior to the attempt with a chest infection, which saw me miss out on a lot of the acclimatization—even walking around base camp had been exhausting. Uisdean also had been suffering from an unknown ailment. John, however, was as strong as an ox, and we were both in awe of his unstoppable momentum throughout the climb.
 
– Will Sim, United Kingdom