I'm hiking on a trail with Sydney. There is one spot where the trail comes to the edge of a cliff, very close, as if the cliff has worn through the trail, and a short rock climb along the edge is required.

I drop down onto the cliff and start finding the hand-holds, which are nice and solid, and Sydney scampers up above through the brush. Looking down, are many hundreds of feet of air, and certain death. Partway across, Sydney comes out of the brush and down the cliff above me, knocking some debris down on me, and seriously risking that she would slip and knock both off us off the cliff.

Concerned, I start climbing back toward the start of the climb, carefully picking my handholds. But then one of the shoulder straps of my backpack comes off my shoulder and gets caught up on my left arm, keeping me from being able to lift it to reach the next handhold.