EDIT: Problem fixed. Found out what I had forgotten to do.
Okay so I know what to do here because I have cleared the game once or twice before, and decided to do it again - because it is probably the best game ever, certainly part of the best franchise ever.
Anyhow, so I got to the top of the ledge where the walkway collapses, and you jump across, and climb the ladder. When I get to the top of the ladder, I follow the water upstream into the cave, and at the end of the cave I am supposed to do the 1-2-1-3 riddle, right.
Here's the thing though: There are no glowing glyphs on the wall. They aren't there. Any thoughts what might have gone wrong? Anything I have missed?
Notes: I picked up the two pebbles but decided to kick seven kinds of hell outta the trolls anyway - seeing as they only cower. I highly doubt this has anything to do with anything but its additional information on how I got to where I am, specific to this scene, so why not.
But yeah, any thoughts? Or am I just blind?