Maybe it’s the mountaineering reading I’m doing this week: Peter Boardman’s magnificent Sacred Summits, which I’m aggrieved to see is scandalously out of print. More on that later, I hope. But I blame my taste for this thrill-seeking on the late Boardman, one of the finest and strongest climbers of the 1980s and one of the best climbing writers of the last few decades.

In any case, this is incredible. I didn’t know one could do this.