Lost Lab of Kwalish

Gravity swallows both of the components along with a small chunk of dried meats then gulps down mouthful of water. She will conjure a magical trinket that vaguely resembles a voltage detector pen by casting Prestidigitation and place it inside the mouth of the restrained lizard. She's trying to determine if the creature is still capable of generating electricity.

Investigation 9

Quote from ikarbino >>

Ana examines the body of the locathah. Investigation or Perception either way the bonus is the same. 25 

 Itz been eaten by lizards, the remai ing flesh beating rhe marks of many small teeth.  The object in its thorax was encased in some sort of sac, tissue possibly from the creature itself, but perhaps not. Close inspection (really this should be a medicine check, but meh) reveals scarring within the remaining tissue, as if some procedure was performed by a skilled surgeon.

Quote from InkedBee >>

Gravity swallows both of the components along with a small chunk of dried meats then gulps down mouthful of water. She will conjure a magical trinket that vaguely resembles a voltage detector pen by casting Prestidigitation and place it inside the mouth of the restrained lizard. She's trying to determine if the creature is still capable of generating electricity.

Investigation 9

 It's definitely charges.  The issue is more of capacitance, where, like the oyster forms a pearl, the mucousal insulation around the generating organ has to build up enough to prevent discharge to the plate running along the creatures back and extending into the ridge of spines along the vertebrae.  Once the insulator is sufficiently thick, voltage potential increases to the limit of capacitance of the organ, at which point a parasympathetic response can trigger a catalytic cascade of mucous breakdown by glucose-fueled cycles of glucosaminase, which become highly efficient when glucose released from the mucosa are abundant. This results in an erratic recharge period based mostly on the lizards present glucose level and current hormonal disposition. 5 

Assuming she has a function meter and a component of k own value, Gravity could determine the capacitance of the lizard.  It is presently in a fully charged state.  The sphere in the locsthah may cause some interference in efforts to measure inductance, though.

(@Wile_E_Coyote, Gravity doesn't have a function meter since she's probably sold it in black-market without thinking about future use.)

Gravity takes short notes of the metabolism system of the creature like a studious apprentice. Then she will ask for the golden armband that was previously worn by the girallon in 'Tomb of Horror'. If others voluntarily let go of the item, she will use 'Tinkers' Tool' to imbue the item with magical property and put it around the front leg of the tiny lizard. It's a tracking device that emits infrasonic waves repeatedly (Magical Tinkering: Sound).

Finally, she will release the lizard by severing the restraint.

Quote from Wile_E_Coyote >>

Assuming she has a function meter and a component of k own value, Gravity could determine the capacitance of the lizard.  It is presently in a fully charged state.  The sphere in the locsthah may cause some interference in efforts to measure inductance, though.

 Typo; intended phrase: "function generator"

The lizard, now banded for identification and tracking, disappears into the murky waters of the dim tunnel.  

<let me know if anyone wants to do anything here or head back out north.  This appears to be a cul de sac.  I do t think anyone took the sphere yet. Still time.  Otherwise, let me know if your ready to move on.>

<So, back out the north corridor then? If yes,  You can continue on your left or backtracks exit the river to the right.>

(Sorry slow to post, back now). I didn’t quite follow-  Tetrevess will search for the magic item in the body of the locolanth, and  Clean it off and inspect it, performing Ritual detect magic and arcana check, while gravity is doing her biology research project.

13 arcana

The sphere crackles with electricity when touched, but the mild jolt is merely alarming, not painful.  While the item seems to cast a light of evocation magic, the means of its construction remain inscrutable to the probing of the arcane master's insightful observations.  The item's construction is far more reminiscint of the objects crafted by Gravity (or any artificer) than the items forged by wizards and sorcerers, through deft manipulation of the weave.  This surgically implanted structures mysterious purpose and origins remain unknown, but Tetrevess' cunning mind deduces what  Thesellar, or whoever devised this horrific procedure, had in mind when he implanted it in the locathah:

https://www.dndbeyond.com/magic-items/3879947-stormheart

(I have not been able to add it as a tooltip, but I will try to put it right in your character sheet. I've done this once or twice but it was a long time ago, so im fuzzy on details)

(Update: it's on Tetrevess' character sheet.  Anyone can add it to their own as long as homebrew content is enabled, but there is onmy one.)

 <note: RAW, I have it as "when you attack...the attack deals [lightning] damage." I interpret my words to mean that the damsge is dealt regardless of whether or not the attaxk actually hits, that is, the lightning damage is dealt not contingent on the success of the attack, but as a separate damage dealt by a bonus action triggered when the attack is made.>

Gravity uses a dagger to slice the remaining flesh of the Locathah out of it's corpse and feeds the sliced pieces to the calf as a reward. "The spherical item seems wicked"- she appreciates the treasure found by Tetrevess while striding towards the water of the tunnel; then dives into it.

“It is an interesting item, to be sure.  In order to work it needs to be implanted into your chest-in which case it will empower your attacks with electrical energy.    Does someone want to use it?” Asks Tetrevess.   “Shall we continue on to the north?”

The calf takes the fishy flesh warily and swallows it down.  After pushing through the water, against the mild current, you return to the tunnel you entered by and follow the water to the left, turning south again.  This tunnel stretched a long way, the silt deposits along the sides dwindling to nothing as you travel south, forcing you to swim (or however you move through the water) as it is increasingly deep (from 6ft at the north end to over 15ft at the bend and beyond, growing to 30ft in depth by the southernmost point) You follow the river south, noticing something on the wall to your left.  it looks like there is a door in the wall beneath the surface.  Further south, you can see the river bends to the west.

https://www.owlbear.rodeo/game/vEYeDXuNa

Everyone has water breathing I believe (tetrevess ritual cast it).  “ hey- should we check out this door?  Tetrevess asks.  

Ana shrugs. "Sure, why not? We should see if it has any traps first, though."

Gravity appears at the surface of the water near the door, blowing out mouthful of water with a 'whoosh' while attempting to mimic the forced exhalation of a whale.

"Should we?"- she responds while fumbling with the contents of her backpack and successfully locating a crowbar. Without further ado, she hurls the gear at the surface of the door to break it down.

Strength (Crowbar): 2, 8

There are no obvious handles on the door, but you do note three evenly spaced holes, each about an inch in diameter, in a horizontal line across the center of the circular doorway made if natural stone, probably originally part of the continuous tunnel wall, the edge cut cleanly around the ce ter in a near perfect circle, the door's diameter being roughly 5ft.

<i think we simul-posted.  I was picturimg it differently, but sure lets go with that crowbar thing working.>

The door rotates in response to the force applied, pivoting  freely when turned 90 degrees, to stand perpendicular to the wall, allowing entry into the room beyond.

Can Gravity see the interior of the room if the door is held ajar? If not...

Gravity sets a dynamite stick/ punk stick on fire and throws the item inside to temporarily illuminate the room. The stick bursts into a shower of polychromatic sparks (Prestidigitation).