Tac Abor, human rogue
"Well, I did sign on to look for this sort of thing," he admits, though it's clear his nonchalance is a show. "I'd venture a guess that we need to clear whatever this is before the arrow will move further. So ... dexter or sinister?" he muses, trying to choose between the right and left glyphs. Finally, he takes a deep breath, says "If this thing comes back up empty, I expect a rescue party," then enters the tube, pressing the right hand glyph.