"I was just helping plan, I don't think I would be especially helpful, especially if you still have a Magic Circle Against Evil to spare."

"So that would be 4 with Ser Seelah and Lann... 5 if we also take the mongrelwoman or one of the cultists to help guide us."

"I know around where the entrance is, but not further than that."

They could just not bother with a Death Ward for Wenduag, she will probably run away anyway.

"I have detect evil myself, but I suppose someone else on alert with it is worth it on the margin.  Do you have any preferences on this Darth Occlus?  I don't know your full abilities, so if, for example, they render Detect Evil entirely superfluous we should leave Ser Seelah behind.  Or if you have abilities to navigate a maze we can leave the mongrelwoman behind." 

"I expect my native senses to be superior to Detect Evil in general, but particularly so in the environment we face, a series of small spaces with walls that may be too thick for it to operate. Taking a guide would speed our progress enough that I expect that to be worthwhile. I trust the Neather for this purpose over the cultists, and I trust the cultists over the Neather to not provoke the Prelate into executing them prematurely."

He would ask what warranted that comment, but she has been here for hours with Count Arendae, so he doesn't need to ask.  Instead...

"Why haven't you executed these cultists yet if you've gotten the useful information out of them?"

"We made a deal to get them to a confessor in exchange for their information."

There are perfectly legal (by Mendev's laws and customs, which are much more realistic and practical than Lastwall's for constant demonic infiltration, and, more importantly are Mendev's) ways of getting cultists to talk.

He settles for continuing to sweep over their surroundings with alternating usage of detect evil and detect chaos.

She is pleased she is already setting herself above the cultists in usefulness!  And that she wasn't identified as a cultist also!

"Alright, I'm ready to set out immediately then.  Prelate, you feel comfortable leading the defense of the Wardstone?"

"Yes, we've broken the cultist's organization, and I can handle any lone demons that try us."

"Then let us be off." Occlus gestures for Wenduag to begin leading the way down the chasm.

Terendelev assumes her human form and follows along.  She doesn't like fighting in this confined space, but she's kept over a third of her magic in reserve and has several foci and holy symbols to support a banishment if she needs it.

It isn't too far actually, a few passages this way, a few passage that way.

She said a guide but didn't actually say no to him, so he's coming along too.

They come to a set of doors, sitting incongruously evenly amid the unworked stone walls of a cave passage. 

One of the doors isn't shut properly, it looks set a little unevenly on the hinges, so it couldn't close all the way.

"It's jammed like that, and the other door is locked.  We could squeeze through, or you could force it open further?"

Terendelev addresses Darth Occlus.  "Do you sense anyone nearby?  I retain almost all of my ordinary strength in this form, so I could just rip it off.  I don't like leaving a narrow point like this at our backs..."

Who knows, the lizard mongrel may even grow as a person on this little excursion.

"I could cut it off the hinges myself, which may be a little quieter." Still, she will stretch out her senses, questing for any thinking being beyond the doors, any hostility, immeninent sources of harm.

There is no one on the other side of the door.  Further away, there are some simple minds, barely smart enough for intelligible speech, performing some form of grunt work they find pointless and frustrating.  Even further away is a similar sort of mind, only slightly smarter, and frustrated to the point of violence.  There are also a few animal minds of some pretty vicious sort of animal.

If she's looking thoroughly, she might also notice three human-like minds, scared out of their wits.

"I think your glowing sword would be quieter, good idea."

It must not be a variant of brilliant energy sword if it can damage non-living material.

"In any case, I sense nothing of more than animal intelligence within."

Occlus draws her saber, and with a few quick motions, cuts through each hinge and then horizontally through the body of the door. She catches it with the Force before it can fall, and twists it around to float it into the interior area out of their way.

"Excellent work!"

The entrance doorway opens into an antechamber.  Past the antechamber, through another doorway, is a long, very wide hallway.  Or maybe it is a central gathering area?  At the far end are rows of pews and a place for a speaker to stand to address a congregation.  It appears the rift Deskari carved in the earth has damaged the Shield Maze, as fallen rubble partially obstructs the hallway about halfway down.

"I can take you to the ritual chamber where they might have the Neathers if they were about to perform the ritual but were interrupted or stopped.  There are one or two other rooms they might be in if they aren't there."