Squeeze yourself down as far under the left side of the roof as you can manage. Start with a right hand in a hollow-sounding flake-pocket, left hand on a smeary non-hold, and butt firmly on the ground. Open up your bag of tricks, and pull out some toe-hooks, bat-hangs and heel-toe cams on your way to the lip. Catch a quick breather, make a hard ninety-degree turn to starboard, and start heading all the way over to the other arete, smearing your heel on wherever you can make it stick. Grab the crimp slot with your right hand, re-adjust it, really get your fingers in there good, re-adjust it again, then swing your feet over and launch into the crux slow-motion dead-point onto the slab.