I appreciate the help you're giving. I have no idea who or what the matriarch is. Starting in the main hall of the Shattered Sanctum, the place where the Priestess does the branding, the spider tunnel is behind her throne. I entered that, talked to the spiders and told them to leave. The only transitional exit in here is called 'Cave Mouth'. Taking that I'm in a different area called the Defiled temple but it's a simple leftward curved tunnel leading to a raised floor with no exit beyond the one I entered through. There's nothing there to explore.
