It is only a few minutes until the cultists and kobolds are past the sewer grate covering the tunnel entrance.  Mr. Black gives it another couple minutes for good measure, then calls the group forward.  He opens the gate once more, and you move out into the slow-moving stream.

Everyone give me stealth rolls, adding the +10 bonus from pass without a trace, as long as you are staying close enough to be under that umbrella.

Art Stealth: 20

Cobalt Stealth 29 

Yassa 35

Zelroch Stealth (w/ Boots of Elvenkind): 37

By the way, backtracking a little bit, while the telepathic bond was being cast, Art was going to do a little healing from his spell-stored staff. 7 charges left.

Mr. Black: 9 (1 charge)
Zelroch: 32 (4 charges)

Dain stealth: 19

You seem to move through the town as little more than a group of shadows. As you do you see many kobolds, cultists, and even some drakes and giant lizards. None of them spot you though, and you soon come up closer to the temple in question.

The temple is a large building, made of fieldstone with a peaked slate roof, and square in shape. It is taller than most other buildings in town.

It is under siege as you approach. Mr. Black and golden Rose quickly scout the area, and determine that there appears to be three different groups besieging the temple. A large force is at the front doors, trying to break them down with a battering ram. A somewhat smaller force appears to be trying to burn their way in through the back door, though that area is lightly obscured by smoke. A third, and larger, group is making rounds of the building, little more than a chaotic mass of kobolds and cultists as they continuously circle the building, waiting for one of the other groups to break through. This third group is about 50 feet in length and takes about 8 minutes to make a full circuit of the building.

"Wait for the roaming group to pass, then assault the backdoor quickly and pull out the refugees?" Art will suggest quietly.

(How big and spread out is the group by the back door?)

"We do not have any means to "quickly assault" anything," reminded Yassa, "or reliably dispose of every attacker. I can try the roof - probably there is a way to bring people one by one that way - one person I would be able to lift - but then we will need some kind of distraction, preventing them all from looking up."

"If you can get inside there, and we can coordinate with them, I can open a path through one of the outer walls and we can evacuate them that way. And I can close it back up so they won't know the refugees have left and hopefully won't know to follow us. And I can make you invisible to get in without being noticed." 

Stone Shape

"I think Art's plan is a good one as much as I relish the next fight, what is important is rescuing the people inside. Then we can attack." Zelroch whispers out.

Mr.Black, "Agree. Find a way in from up top, then lead them through a side wall and away. Stealth now, battle later. Yassa, I'll meet you on the roof."  Mr. Black, flies up into the air, using the smoke as cover and gets to the roof, and begins looking for a way into the temple from up above.  

"Then this is the plan." Yassa would not mind if Art uses his Invisibility spell, and as soon as it's done, follows Black to the roof.

Mr. Black and Golden Rose are able to get into the temple through a chimney they found on the rooftop. You two come out in a kitchen, that is empty currently, but can hear the sound of a loud thud coming from out the door of the kitchen. Going that way you see a bunch of townsfolk milling around, clearly all scared and looking worriedly towards the front door, where yet another loud thump comes, the sound of the ram hammering into the door. The townsfolk look near panic.

Cobalt will follow Mr Black and Rose by wild shaping into a bird to fly up and down the chimney after them. Turning back into his normal self in the kitchen. Upon seeing ht townsfolk, "Hello. We have been requested to secure your safety by your mayor. I am Colbalt, if any are injured, I can be of assistance,"

Zelroch whispers to Art, "Did we decide which side of the church we should use for the townsfolk's escape? Shall we go look at each side to see which side would be best to use for their escape, one with the most amount of cover or at least cover they can scramble to quickly? And we determine what side to use, how will we tell them which way to go? If I can find a rat nearby or a bird, I can talk to them and ask them to help for a sizeable treat."

"Some additional distraction might help as well at the moment of door-making," chimed in Rose, still invisible to the crowd inside, "if everyone is busy, I'll do it when everyone is ready to go."

Art would have made Rose invisible before sending her in.

"The telepathic communication lets us coordinate, but yes, we should find the best spot to pull them out. And while I don't know that we need to distract the people at the doors, a brief distraction to the roaming group on the opposite side from where we choose to exit might help. Dain, Thueban, why don't you check the left side (from the back door), Zelroch and I can check the right."

"Sounds good. I will report in a moment."

Theuban casts invisibility on himself to balance against his generally poor stealth abilities.  Then with a burst of divine energy to provide insight (Channel Divinity to get proficiency on Stealth for next 10 minutes) he edges away from the back door towards the left side of the building.

Stealth: 37 (Pass without a trace is still up right?  otherwise take 10 off of this).  He is invis though, so this is more about how quietly he is moving, not how well he is hiding.

Perception: 10