There are a series of podcasts online here in which John reads sections of his play, the most climbing related section is embedded above in which John Burns explores how Crowely became a climber and reads stories from his confessions, from Wasdale Head to the Alps.
Crowley was a fantastic climber, perhaps due to his madness, although some say due to his super human powers... and in March 1902, partnered by Oscar Eckenstein Crowley made the first attempt to climb K2 in Pakistan. Leading up to that he climbed extensively in the alps and also made cutting edge first ascents on British rock, perhaps most famous is his audacious ascent of Etheldreda's Pinnacle and Crowley's Crack on the loose and serious chalk cliff of Beachy Head way back in 1894. It's worth noting that these climbs are now graded VS and HVS and it took many years (70ish!) for them to get a second ascent!
Here John Burns introduces Crowley:
"Aleister Crowley was one of the most controversial men of the 20th century, he was a mountaineer, a poet and a chess grand master but he is most remembered as the world's greatest expert on the occult, a man whose magical powers have no equal. Crowley was reviled by Victorian society as he cast aside its religious and moral strictures and sought to find a new faith in the teachings of the occult and, what we today, would call black magic."
- You can read more about Crowley on his Wikipedia Page.