SecretOwl sheathes his daggers and helps @Psycho_Mycho move the body out of the light and into the shadows. Then he decides to draw his bow instead of his daggers. It will be easier to stay hidden if he dispatches any thralls that appear from a distance. He nods to @Psycho_Mycho and ducks back into cover to ensure the path remains clear. He nocks an arrow and slows his breathing as he aims down the empty corridor.
Once @Skwid finds what could be the glyph on the right side, SecretOwl leaves @Psycho_Mycho to continue searching the left side and circles back to support @Skwid. If the Thrall near @Skwid becomes aware of his presense, SecretOwl will jump out of the shadows and attempt to take him down. Otherwise he will remain silent and still in support.
According to @TheWizard the often discussed and generally feared Black Key did not cause the collapse. We now know that someone name Edyrin Zahn is the cause of all the mayhem! I for one cannot wait to learn more about this person.