"Many rooms" - she can sketch them a rough (and partial) map. "It eventually connects to another door at the far end of this hall."

"Probably chasing the cultists through those rooms is safer, then." Even if she doesn't get to show off by flying about it. 

Then they can carefully approach the next half-open door!

Ha ha, did you think we'd wait for you on the other side of that door? We're not that stupid!

Obviously we ran away as fast as we could to get help. By which we mean, to get someone else to fight you. We've been honourably wounded in the line of duty, and deserve a raise a rest.

The next room is fairly large and has three other doors; Wenduag doesn't know where they all lead, but the one on the left is the one that would let them eventually double back to the long hall.

"The wounded one was dripping blood, look..." The trail of blood drops leads to the door at the far right corner.

That door it is, then. 

That door has stairs leading down into a partially-flooded room; the water level is shin high. Throwing Lighted pebbles in various directions reveals a set of barred cells (empty), two doors (one of them after a few stairs up, so it probably leads to a non-flooded room), and a short corridor ending in rubble that looks like it connects to bare rock in the process of being excavated.

The two doors are fairly close together. "Left door, right door, or open both at once so we're not ambushed?"

"I'd rather bar one door while opening the other, but if we can't do that, open both doors." 

"Bar them how? I can hold one shut by force, if I'm not fighting."

Lucette throws another Lighted pebble, looking for a rock big enough that it would take both her and Seelah together to lift it. 

There are rocks of all sizes over at the unfinished end of the room! They can carry one or two over.

Unfortunately, while they're trying to do that, the leftmost doors bursts open, and three men with glaives run out at them! 

At least they weren't by the door when it happened, which means they're not attacked right away. (The wizards with crossbows are prudently staying far back of the fighting this time.)

The first thing Lucette does, obviously, is start singing. Have plus one to hit and damage, allies! 

The last thing the man in the lead did before opening the door was cast bless, so now he'll obviously cast bane.

The other two charge ahead, but the water makes running hard and with the three archers backing away, Seelah can intercept at least one of them.

Camellia has her own magic bonuses and is happy to run forward to stab people when her party has two healers in it!

Some of her battle-cries might be a bit disconcerting, but really battle cries are meant to frighten the enemy, right?

As long as Camellia sticks to stabbing cultists and demons, Lucette basically does not care how much she enjoys spilling their blood. 

She's also pretty good at swording cultists herself. 

With three melee combatants to hold the enemy back the three archers are free to focus their fire on one of them, until pretty soon Lucette's opponent is trying to fall back behind the other two.

On the other hand, the enemy cleric is giving Seelah enough trouble that she's rapidly running down her uses of lay on hands!

"Wizard maggots! Get your asses in here or I'll kill you myself when I'm done!"

Thus encouraged, the two wizards from before start taking turns at peeking out of the door and firing more poorly-aimed crossbow bolts and one last magic missile at Lucette. They don't have good enough aim to try to reach the archers in the back, and she doesn't look heavily armoured, right?

The chainmail doesn't obstruct either crossbow bolt quite enough, but her scales do! 

The magic missile goes but she doesn't go down, and now Lucette has the opportunity to sword at the cleric. 

He won't go down that easily! But he does have to stop fighting to cure himself.

...this isn't working, his glaive is great for reach but once people with rapiers and swords get inside his guard it's pretty much over. Glaives, like longspears, are best used in a fighting line, or better yet several lines, but for servants of Baphomet this has the obvious downside that the rear line is liable to backstab you and/or run away. Normally he'd rush the enemy archers, but the water makes that hard.

He retreats back toward the doorway, where there isn't enough room to surround him. His other subordinate (the one who hasn't yet earned himself a punishment by fleeing) can be the front line / meat shield, while he glaives at people from behind. And the wizards had better have some extra scrolls.

Who's going to be the enemy's point man in this hopefully one-on-two melee?

We don't have to follow you into melee, you know, we can just keep shooting at you all day. Because we have three real archers, not a bunch of wizards with crossbows.

Damn it, the melee was fun!

The two wizards do each have an emergency backup scroll!!

...one of them is grease. (Are they going to die because they didn't deal with the water elemental like Hosilla told them to?! Out of everything they've done, is that going to be what kills them?!)

The other scroll is -