After Zath'ras has thoroughly searched the Eastern end of the corridor and found nothing but wall he says mostly to himself, "Svirfneblin not be building this, this being useless." he gestures to indicate the eastern dead end corridor. Getting back to the group he stops and asks Meepo in Draconic, "Who Calcryx is being? As he waits for Meepo's reply he begins to examine the northern door for traps as well as listen to see what he hears on the other side.