Of all the stories in climbing’s history, the tales of the routes that don’t give in are the most fascinating and strange. Ed Douglas investigates the hidden space between success and failure in the vertical world.

Soon we’ll go down, into the shadows. But for now I stay where I am, crampons rooted in the snow, a knee braced against the slope, at 5900m on the southeast ridge of a grand and unclimbed mountain in western Nepal. There’s bright sunshine above, while ahead straightforward snow and ice leads toward the summit ridge. And yet we’re done. It’s over.

The bad news is sneaking up behind us, scudding dark clouds typical of the unsettled weather we’ve endured for the last few weeks. It’s taken us over seven hours to get here, and we’re only going to get slower. We don’t have any gear, having ditched our original plan of placing a camp more or less where we’re now standing. The weather has robbed us of too much time. If we go on now, we’ll get a bit higher, turn around anyway and probably get caught by the bad weather coming in. Time to go.

Even so, I’m reluctant to leave. It’s taken weeks to get here, on top of all the planning and cost. I’m just about the least ambitious climber I’ve ever met, and yet the frustration is bubbling away inside, like heartburn. I’m not getting any younger, and this mountain really is worth the effort. I kick fresh steps in the snow and look up again. Were I younger, tougher, or more motivated, I’d take a chance and carry on, accepting the consequences. But I just don’t think it’s worth the risk.