Description
Inspection of the troll brains suggests two things. One: they are too small to support language. And two: the trolls have some telepathic ability.
Perform an experiment of your own. Examine the troll glyph west of here to see if there's anything you can learn.
Upon completion
It sounds like I wasn't wrong about the telepathy. You received a mental message, only your brain isn't tuned to receive it. I wonder who really made the troll glyphs, and what are they communicating?