The ridge I know by heart has moved

I'm guiding a group up the east ridge — the one I've done maybe two hundred times, the one I could walk in my sleep. Only the rock isn't where my hands expect it. Every hold is six inches off, like the mountain shifted in the night and didn't tell anyone. The clients don't notice. They're chatting, taking photos. I'm the only one who feels how wrong the geometry is, and I can't say why it scares me.