Binder's Hold and the Problem with the Mine.

It was situational if someone came into melee range.

AH, I missed that from earlier.

Are we still waiting on Kumiko's & Gema's  Turn?

Kumiko growls in anger and  she blasts her own sacred flame at him. DC 16 DEX or 11 Radiant Damage

4

And with Kumiko's attack, the druid goes down, which quenches the heat metal on Zelgius. 

Gema, there is still the other caster & fighter to the west about 120' away from you and the two lizardmen to the northwest 90' (in dim light).

OK, the two remaining lizardmen that were with the Druid (group 3) continue fleeing to the northwest out of sight and you hear a couple of splashes...

Initiative new round:

Group 1                                 23

Aegnor & Shadow               21

Guile                                      17

Vanja                                     13

Group 2                                  All Dead

Skeleton                                13

Kumiko                                  12

Gema                                     10

Bridgette (Dex 17)                 7

Ravager   (Dex 16)                 7

Zelguis                                    2

Group 3                                   2

Group 1 (The Spell Caster and Fighter type) run out of sight around the corner to the northwest in a separate tunnel, after which you hear another couple of splashes.

Aegnor readies an action.  After Skelly is sent north, He and Shadow follow behind. If an enemy is sighted attack with eldritch blasts while Shadow guards and protects.  "We'll scout a bit north where they disappeared with splashes for intel."

Aegnor sends Skelly north 20 ft and dash 20 ft.  Aegnor and Shadow mover 30 ft behind Skelly alert and scanning their environment for anything unusual.

Guile seems perturbed as to not have bested the arcane caster.  "We have a means to follow, thanks to the scroll of Water Breathing I found.  It would take some time to perform the ritual...  I can begin while you scout ahead and see if the there's another way." 

Guile sends his familiar to explore the chamber for other tunnels.

"Bridgette & I can follow immediately using our items." Ravager mentions.  "Say when."

Vanja brings up the rear of the group following, scanning to the side and back as they progress. 

Bridgette simply nods, mentally preparing herself for the next unpleasant encounter.

"So are we swimming or what?" asks Ravager.

After a few minutes, Guile finishes the Water Breathing ritual.  "The spell will last a day.  Long enough to follow where the lizardfolk have fled.  If there's nothing else here, let's follow..."  

Guile pauses a moment to look over the cave and the mushrooms grown.  "I would think the lizardfolk prefer meat. Are these simply a food source?" Nature: 17

Guile isn't sure if the fungus is a just food source.  His Passive Investigation immediately notes that the majority of the fungus are long, wood-like structures that might be suitable to be worked like branches from a tree.

A quick look through Nox's senses shows him a stretch of beach (about 120' in length and 25' wide) that sits along a great expanse of briny water... perhaps an underground sea?

No other land masses are within sense range of a quick flight around.  

Aegnor comments, "Does the way both groups went into the water go to the same area?  If so, then we can proceed when everyone is ready.  If not, I don't recommend splitting up.  Skelly doesn't need water breathing but Shadow my dire wolf will need it.  Thanks Guile"

Aegnor takes and combines all his stuff into one sack to help keep the water out and everything contained in the sack or backpack as much as possible securing loose stuff as best he can too.

Vanja absently picks at the mushrooms, popping a bit into her mouth before spitting it out in disgust. "Yuck. I hate mushrooms."

She flexes her muscles. "All ready? Let's go then. Looking forward to trying out this underwater breathing!"

Good news, per Jeremy Crawford, you can cast spells with verbal components underwater.  Though he mentions that if you are holding your breath and cast a verbal component spell you immediately start drowning.  Luckily, you all have water breathing for 24 hours!

(posting new map in a few minutes.)

Hmmm.. didn't post my map!  and still won't do it.  Posted it 3 times now over a period of a day.