(I just re-read Moan. It lasts to the end of the Cloaker's next turn, so no additional save necessary.
You could attack with disadvantage while frightened, but spells like Bonfire are a way around that.)

CON save for spores: 5

DEX save for bonfire: 18

Hildigrim and Jorin still to go. Then I'll add up the damage to see if it is still flying or not.

Even with advantage, I still miss the mark.

Volo's freight reverberates in Hildigrim's head through their telepathic link. That, coupled with the memory of the cloaker wrapping itself around his legs and quickly trying to climb up his tiny body cause the halfling to shutter. He throws his hands up over his head in a defensive gesture (dodge action) and yells something helpful to Jorin that sounds a bit like "Kill it!!!"

Drusk attacks with his mace, but was so caught up with "singing" with the cloaker that he misses (rolled a 1 in the Game Log).

Jorin is up.
He did move next to the cloaker last turn, so even if frightened he is already in melee range. And Hildigrim Help-fully suggests smashing it in the mouth.
If frightened, first attack is normal, rest are at disadvantage,
If not frightened, first attack with advantage, rest are normal.

Got an 11 + 2 from bless in the game log, so Jorin just makes the wis save.  He will attack the creature savagely, but sans rage (only one rage left and i feel like i should save it for the return trip if anything bad happens).

• Reckless battleaxe attacks
  • First Attack: 25 Damage: 9
  • Second Attack: 24 Damage: 8
• Reckless moon blade attack
  • Attack: 25 Damage: 8

Sad rolls :(

Between Feldspar (12 bonfire damage), Quillary (10 club+spores), and 3 hits by Jorin (25 damage), an additional 47 damage is done.
The booming Moan turns into a hacking noise. The Cloaker crashes into the ground, and after a spasm moves no more.

Combat is over.

The book the ulitharid was carrying burns up in the bonfire.
(It was a macguffin, so it seems more satisfying to have an evil illithid book be destroyed by your actions, rather than tempt Hildigrim to claim it.)

Drusk will use one of his Channel Divinities to give the eight regular scouts 5 points of healing apiece (all of them were at 1 hp).
The party uses the last remaining temporary healing potion on the leader of the scouts. He grimaces at the foul taste of the concoction, but still thanks the party for saving their lives.

As soon as Hildi notices the book burning merrily in the fire, he lets out his own moan.

Quillary goes to check the captives. They are all members of the patrol? No denizens of the underdark?

Feldspar's fear breaks, and once the cloaker gets chopped up and burned and beaten and... spored?... she quickly walks around the perimeter of the room, looking for any hiding creepy crawlies to stab. Any open or closed doors or openings (to also stab). Anything but the captives, who are being healed and handled well, and the dead beasties, who got inside her mind. She really doesn't like that. Once she spins down she ends up in a heap, relatively uninjured but pretty tired. Likely next to Quillary, at times looking at and listening to the captives.

"Well, what happened? How'd you get here? They get inside your mind too?" she says to the captives after they've had a chance to recover a bit.

Jorin watches the book burn and a small smile pulls at the ends of his mouth before he goes and helps unbind the captives.

As the flames around the mind flayer die down, all the party members see a vision. (Put in a spoiler for convenience.)

The leader of the scouts introduces himself as Captain Brannigan. He answers your questions to the best of his ability.

The other 8 scouts are all that are left of the the 3rd team and his team (the 4th one).
The first 2 teams are long dead, as well as the other drow who were hunting this ulitharid. (Some of their clothing and bits of equipment are scattered around the cave, but most of their remains were eaten by the cloaker or used to create the Banderhobbs.)

Brannigan and the 4th team were able to track where the other teams had gone, but were ambushed by Banderhobbs. They gave chase when two of the scouts were abducted/swallowed, and walked into a trap set by the ulitharid and the cloaker. Caught off guard and overpowered, they were beaten until they couldn't resist anymore, and were waiting for their deaths by the spell ritual, before your party saved them.

Drusk gives them some of the standard army rations your group picked up at the Citadel.
(He doesn't give them any of the good food that Pascal packed for your trip, as it might be too spicy and rich for them in their weakened condition.
Or that is what Drusk claims is the reason.)

The scouts look around the cave for any equipment that might help for half-day trip back to the Citadel: cloaks, jackets, daggers or anything that can be used as weapons.
While Brannigan is answering your questions, he absent-mindedly rubs the ring finger of his right hand, where there is a tan line around the finger (but his hands are bare).

Quillary tries to recognize the woman from her recent studies of drow culture, but (Religion igl: 5) recalls nothing much. Lloth? Some other drow goddess? Just a powerful wizard/cleric? Who knows. Pretty.

As the vision clears, Quillary sinks down to sit on the ground. She fumbles in her bag and pulls out a small bound book, opening it and flipping through the pages absently, almost like she's just looking at the pictures.

After the vision, and while the others are beginning their questioning of the survivors, Hildigrim spends a minute looking around for arrows that could be used again. He finds one.

5+1=6

He also tries to place the drow woman. (Religion: 14)

Finally, he joins the others in their search for answers. The information is nothing they couldn't have intuited. However, when he spots what is clearly a missing ring on the man's finger, he says excitedly, "The ring!" He looks at Feldspar and Drusk. "Which of you ended up with it?"

Feldspar looks at Drusk -- she thinks she handed over the ring to him after the Banderhobb fight...

Jorin quite enjoys The Lady's kiss and lingers with his eyes closed a little longer than the others before saying somewhat absently, "I should like to find her some day..."

Drusk Religion roll in Game Log: 7
"That wasn't Lliira, and there are a lot of gods who can resemble anyone they want. When we get back to the Citadel, I'll try to do some research."

Quillary looks through the small bound book. With the tiny size, the drawings inside are limited. Also, the drawings are not true to life, so if she was hoping to get inspiration for who the vision woman was, the book does not help. The drawing are both over-idealized and exaggerated. (Think Mannerism style, like Parmigianino's "Madonna with the Long Neck", except the artist who made the tiny book is not as skilled)

When Feldspar asks Drusk what he did with the ring they found, he fishes around his coin pouch and eventually holds out the ring (pieces). The Captain gives out a delighted gasp. The signet ring is for a unit commander in the Lord's Alliance, and as you already noticed, has Captain Paz Brannigan engraved on it. The Banderhobbs removed anything of value from the captured scouts. When Brannigan resisted giving up the ring, the creatures gave him a kick in the face, stomped on the ring (breaking it) while croaking (frog-laughing), and took the broken ring with them.

Besides the sentimental attachment Brannigan has for the ring, the loss would have been humiliating for the officer and the replacement fees outrageous. He promises a finder's reward, once you are back in the Citadel and he has access to his normal possessions. Drusk asks Hildigrim to use Mending on the ring loop. With a little time spent to get the pieces properly lined up, the ring is still battered from long use but you can no longer tell it was ever broken.

Although you will be on the edge of exhaustion, you decide it is better to get back to the safety of the Citadel rather than risk trying to sleep in the Underdark. The cave may be a save haven for now, but you are noticing the reek of the dead creatures and the scouts do not want to be reminded of their dead colleagues.

Your group has more adventures on the way back to the Citadel, but they are more annoyances than actual peril. (It is also shorter, since you are retracing your steps rather than searching for traces of old scout footsteps. Brannigan helps greatly in the path finding.) More molds (yellow and russet) have grown over paths you found clear hours ago. The tired scouts almost wander into a cave infested with piercers before you get them back on path. The worst are a pair of ropers hanging on the ceiling, making it difficult for Jorin to reach them with his axe. After that encounter, Hildigrim is down to his last arrow, but is still clutching it when you get back to the Citadel. (Hildigrim's inventory can be reset to 20 arrows again, with another 20 in the bag of holding, as he definitely goes shopping when he has a chance.)

At the Citadel, there is much rejoicing at the return of the survivors, and a moment of silence for the scouts that perished. There is a quick overview of what happened in the Underdark, but they will do a more complete debriefing in the morning, before the magical gate back to Waterdeep will be arranged at noon.
There is much feasting at a celebration.
(Drusk secretly passes out the food that Pascal prepared before you left. While you are polite and pretend to eat more than you have, these are the same army cooks who made the standard rations.)

That night when you sleep, your dreams are very disturbing. (Put in spoilers for convenience.)

Quillary awakens angry and determined. “This foul woman is not what I know of the dark elves,” she mutters. Then she, much to everyone’s surprise, asks after and then goes to whatever library the citadel has, where she hunts for everything they have on drow goddesses. Someone will have to retrieve her.

OOC: Did Hildigrim know anything with his 14 religion check earlier?

Hildigrim wakes, fretful and hungry. When he hears that Quillary has escaped to a library!, he follows her there to help in any way he can (after eating, of course).

OOC: Remember that Hildi's background is sage with the feature of researcher.

Far from retrieving her, Hildi helps Quillary dig in even more. In fact, she doesn't stop for sleep or food (neither of which she needs, being officially dead), dropping into a trance every now and again to process what she has learned. She quickly homes in on whatever content they have on Eilistraee, the "good" drow goddess responsible for countering Lloth. The Dark Maiden (as she is known) works hard to bring drow out of Lloth's clutches. As such, she seems like a good ally. Quillary devours everything she can about her and her priestesses, even returning from one of her trances with some unexpected knowledge to supplement Hildi's researching skills. (See Reborn feature: Knowledge from a Past Life)

Suffice it to say, whatever the citadel's library has on Eilistraee, she uncovers and devours (metaphorically speaking, though she will be caught tasting a page at one point).

When Quillary and Hildi miss lunch, Jorin becomes concerned and gathers up two burly arms worth of lunch nibbles and a few flagons of ale.  He takes those to them in the library, likely sloshing a bit of ale here, dropping a few morsels of food there, take a bite and slurp for himself a few times as well, but by the time he finds them, there is plenty for them to nosh on.