The Collapse

I have created and bound Alluvius using the Horn of Elemental Fury. He will respond to the horn's call when you stand near the southernmost sinkhole in the Geyser Fields.$B$BThe quake Alluvius will unleash should collapse the Nerubian tunnels and put an end to their flanking attack. I wouldn't be surprised if the Nerubian commander showed himself after the quake. If the collapse of the tunnels doesn't break the back of their assault, the defeat of their leader surely will.