Flint sends up more of the black tentacles he used previously to block Grung. However, Grung evades them, having three directions to go, before he disappears down the hall above you, where he is out of sight.
It is his scream a moment later that sends you all running up the stairs.
Kahan reaches him first.
Syrissa is standing next to Grung, wrenching the Augmantium box from his hands. Grung is not moving, and then you see why. Grung is now a statue, just like the many statues that adorn the area below.
Syrissa hands the Augmantium box to Kahan. A brooch is also around Grung's neck, and she removes it and gives it to Kahan too. It is the other artifact from the Dwarf compound. The rest of Grung and his equipment has turned to stone.
"I'm sorry," she says from behind her veiled mask. "I heard the arguing and the fighting. We need this artifact for the Ark, and I had no choice. The sacrifice was necessary."
Edmure appears at the far end coming towards you, his ancient face and blind eyes searching as he walks down the hall. "It is all right, my dear. You have done well for so long, and this was the lesser of the evils."