A team of young French alpinists has climbed a major new mixed line in alpine style on the 2,100m south-west face of Latok II in Pakistan's Karakoram range.
Due to unsettled weather Antoine Bletton, Pierre Labbre, Mathieu Maynadier and Sébastien Ratel were only able to acclimatize with one night at 5,800m, before receiving a text message that there would be a three-day weather window followed by 10 days of snow.
Despite feeling three days was not enough, the four moved up to the base of the wall and bivouacked.
On day one, after crossing a difficult rimaye, they moved quickly up the initial 500m snow slope. At its apex a crucial leftward slanting weakness would allow them to bypass a steep granite rock barrier.
Snow, ice and mixed climbing on this ramp ended with spindrift-swept ice runnels and "Ben Nevis ambience", before they reached a poor bivouac site.
After a cold and difficult night, two mixed pitches led to more snow ramps and eventually a hanging snowfield high on the face, where they made a more comfortable second bivouac.
On day three they got up at 2am and reached the ridge at 2pm after some difficult and delicate mixed climbing. Two more mixed pitches on the crest led to the summit plateau at ca 6,700m.
Leaving sacs and most of their technical gear, they arrived at a small "top" at ca 7,020m.
This was not the main summit of Latok II (7,108m), still almost 100m above, but given the lateness of the hour, and the approaching storm, they dubbed it the Southwest summit and beat a hasty retreat, fearing large avalanches on the lower slopes, should they be caught there in bad weather.
Just after midnight they regained their bivouac site, where they filled Thermos flasks and continued down.
Despite falling asleep on belays, but taking care to constantly check each other's actions, they made it to the rimaye at 10am, picked up skis, and were back at base camp by 1pm.
The route has been named Théorème de la Peine (ca 2,000m, ED1, M5). In 2010 Maynadier and Ratel were part of a team making the first ascent of 6,830m Lunag I Southeast, a climb nominated for a 2011 Piolet d'Or.
Immediately left of their new line on Latok II, the west face is characterized by a huge central couloir. At around half height on the face, this couloir slants steeply up left below a precipitous rock headwall to reach the crest of the northwest ridge.
In 1998 Franz Fendt and Christian Schlesener followed the couloir to make the first ascent, in alpine-style, of the upper northwest ridge, a route tried integrally over the years by several British parties, notably in 1987 when an expedition led by Joe Brown reached 6,800m.
The 2,400m ridge was finally climbed throughout in 2009 by Spanish Alvaro Novellon and Oscar Perez, though sadly Perez perished during the descent.
The huge headwall on the west face was also climbed in 1998. Conrad Anker, Toni Gutsch, Alex and Thomas Huber completed this 2,200m climb, capsule-style, at VII 5.10c A3, creating the hardest big wall route at altitude for the time. Alex Huber dubbed it a landmark ascent, but Anker was less happy with the amount of drilling that had been deemed necessary.