Supported by grants from the BMC, Mount Everest Foundation and The Alpine Club, Malcolm Bass and Simon Yearsley climbed to a point 140m below Janahut's virgin summit, where late in the day, and with the prospect of a difficult descent, they opted to retreat.
The unclimbed Janahut (6,805m) lies in the Gangotri region of the Indian Himalaya, and had seen five previous attempts.
It was the goal of Austrians Josef Jochler and Christian Zenz in 2002, but the weather was so poor they were unable to make a serious attempt.
In 2004 it was tried again via two different routes, but by teams from the same expedition.
New Zealanders Marty Beare and Pat Deavoll made a valiant attempt on the west face, reaching 6,400m.
At the same time Malcolm Bass, Andy Brown and Paul Figg tried the southwest buttress and ridge, but descended from 6,000m.
In 2010 and 2011 American Bryan Hylenski and team made attempts from the southeast. They used fixed ropes and reached a high point of ca 6,500m.
In 2013 Hylenski had planned a third attempt but the huge and devastating mid-June flash flood in the province of Uttarkhand, where the Gangotri is located, prevented access.
Bass and Yearsley had hoped to have another crack at the southwest face of Rimo III in the Indian East Karakoram, which they attempted two years ago.
However, this year their application for a permit was turned down, so Plan B involved peaks around the head of the Gangotri Glacier.
They started up the southwest buttress of Janahut at 1am on June 10.
Climbing unroped up snowfields and short gullies, they reached a well-protected bivouac site at 10am, and at an altitude of 5,900m stopped for the day, sheltered from the rock and icefall that began when the sun hit the face.
At 2:30 the following morning, with the face firmly frozen, they started upwards, moving together over pockets of windslab.
Weaving through granite towers, it was a relief to emerge finally into the sunshine. The morning had been ferociously cold with temperatures down to -30°C
A scratchy rock pitch and a few ropelengths along a ridge brought them to a hollow beneath a large gendarme. The height was 6,300m, and this seemed a good jumping off point for a summit attempt.
At 4am on the 12th they left the tent at this eyrie and set off for what would prove to be a long, superb and exciting day's climbing.
A few pitches of hard ice, a long horizontal section of snow ridge, and occasional technical sections through short rock steps, led to an 80m granite barrier they dubbed The Castle.
Two hard mixed pitches led to a short wall at the top, from where they could see the continuation ridge leading over a foresummit to the highest point.
It was 6pm, the altitude was 6,660m, they had been climbing for 14 hours, and it would be dark in another two.
As the freezing wind strengthened, it was deemed time to go down.
They regained the tent 21 hours after leaving, by which time they were very cold.
They spent all the 13th sleeping, eating the remainder of their food, and planning a descent of the shorter, east flank of the mountain.
Leaving at 9am on the 14th, Bass and Yearsley reached the glacial basin below the face at 8pm. Their evening meal was two cups of tea each, using bags scavenged from the rubbish sack.
Next day the descent to the campsite at the foot of the buttress, where they had left a small stash of food, proved surprisingly straightforward. All that remained the following day was a 10-hour trudge down glacier to base camp.
Thanks to Simon Yearsley for information. Both Bass and Yearsley are sponsored by Montane and Lyon Outdoors.