Cassian will breath a sigh of relief as Navrine is healed, offering a hand to help her up.

"T-that was close. Too close," he remarks, wiping the sweat from his forehead. Hearing Doc's question, he will add, "The same t-thing that gave it fire properties, I imagine. I-it doesn't make sense for a natural spider to burn its own webs and food."

Cassian will retrieve his javelins and examine the spider corpse more closely for clues.

Investigation 23

Con save 6 (Fail death save) 

She feels dizzy not quite sure what happened as healing energy surged fighting the flaming venom coursing through her veins. “Am I going to die?” she thought “If so death hurts.”  She looks up at Cassian’s hand  “Thanks.” She grabs his hand and pulls herself up.  She looks at the dead spider and softly says “Not today.”  She dusts herself off and turns to Doc “Thanks for the save Doc.”  

The heroes moved cautiously through the scorched laboratory, also examining the smoldering remains of the fallen Inferno Spider.

They noted its unnaturally large size and the faint, residual heat still radiating from its carapace. On the floor, after brushing away soot and ichor, they discovered fragments of broken glass embedded in the webbing near the spider — remnants of shattered potion bottles.

It became clear that the creature, like the giant rats encountered previously, had probably ingested several magical potions.

Indeed ... for this particular spider ... it looked like it had consumed a variety of these potions.  Unintentionally mixing them.  Combining these potions had twisted it into a monstrous form, a reminder of the dangers of reckless alchemy.

Turning their attention to the ruined lab, they found most of the equipment too damaged by flame and time to be of any use. Blackened glassware lay shattered across the floor, and metal instruments were warped and rusted. A faint glimmer, however, caught their eye.  Amidst the ash-strewn remains of a bookshelf lay a single book that had not succumbed to the fire and rot of ages.  Its cover was singed, but intact.

The pages crackled slightly as it was opened, revealing arcane symbols and spells untouched by the flames. 

A spellbook!

"Potions again," Cassian frowns as they spot more remnants of the broken bottles, "We need to f-find where the wizard was storing these things."

When they uncover the spellbook Cassian's immediate reaction is curiosity with a healthy dose of wariness. He grabs one of the small metal tools nearby and uses it to flip through the pages, not wanting to risk touching the book directly after seeing how dangerous just the potions are.

Investigation to try to discern what spells are listed: 15

Cassian reviewed the long-dead wizard's spellbook for a few moments.  Nothing.  None of the esoteric formulas or arcane sigils made one bit of sense to the paladin.

Determining the contents of a spellbook is outside the scope of an Int (Investigation) roll.  Swapping the results to an Int (Arcana) roll instead ... It is still outside the scope of an Arcana roll to determine the contents of a spellbook, but Cassian recalls that the only person who can read a wizard's spellbook is the wizard who scribed it.  Outside of that, magic would be required to decipher its contents (via the spell, Identify).

Chromir collects his javelins and then goes around stomping on any tiny spider that might be left (harmless or otherwise) while the rest of the party search the room. And as I suspect we spend more than 2 minutes in this room, his rage will end. Once it does, he will be able to use his very limited magic so will cast cure wounds on himself bringing himself back to full health.

"Everyone ready for me to open the next door? If its locked I can try force it open and if there is an ambush, I can take it."

"Another wizard might want this, I-I think. Either way it's probably safer not to leave it laying around." Cassian will reluctantly carry the book only if no one else moves to take it. "I'd l-like to go back and check that other door (North one from the previous hallway). It was unlocked so checking it shouldn't take l-long."

Navrine nods in agreement with Cassian “ We need a clear path to escape if need be.” She looks at the door in the room just a bit scared after her close call “There could be enemies behind both doors, and if we don't check the north one they could ambush us as we are trying to leave.”  Knowing fully that she ultimately will follow whatever the group wants to do. Still she feels uncomfortable in this strange dark place. “We should be methodical in our exploration, and careful.” That last bit she mused applies more to her than anyone else, no more blindly charging monsters for her.

Doc is fine with putting the spellbook in his bag, and says "Well I didn't feel any creatures there, but that doesn't mean there couldn't be anything flying around."

The heroes doubled back to the northern room.  Opening the door, their boots stirred a fine layer of dust that coated the uneven stone floor.  A pantry of some kind with shelving along the far wall.  At its center, a large stone well.  The wooden handle above it and the remnants of a frayed rope dangled uselessly into the dark, yawning shaft below. The well exuded an unsettling sense of emptiness, the kind that seemed to swallow sound and light alike.

To the far right, a shaft of weak sunlight filtered through a small, jagged hole in the collapsed ceiling.   Dust motes were illuminated by this shaft of sunlight as they floated aimlessly. The faint golden glow failed to brighten the shadowy corners of the room, where one might expect scurrying vermin or the signs of long-forgotten life. Yet, the room was eerily devoid of any such traces—no claw marks, no discarded bones, no droppings, nothing.

Although his Stonecunning was nearing its end, it was still active.  Doc detected no movement whatsoever in this room.

You can't shake the feeling that something isn't right here.  Please make a DC15 Nature or Investigation roll (whichever you prefer) with your next post.

Navrine doesn't like the look of this room. “I really urge caution here guys. Something is off here.” She looks carefully around.

(Investigation 5)

“Should we  investigate the other door?” She again scans the room for danger “this seems clear but it's probably trapped”

Cassian nods at Navrine's warning, also casting a careful glance around without moving further into the room.

Investigation 15

"Strange p-place for a well," he remarks, feeling an ominous aura from it.

Given that the rest of the cellar level was infested with vermin, and this used to be a pantry of some kind, with access to fresh water, and clear access to the outside ... 

... there really should be more  signs of animal life ... not less.

The room is giving 'It's quiet ... too quiet" vibes.

Still unable to pinpoint what is going on with the room, Cassian murmurs the incantation for detect evil and good. Perhaps this place is desecrated somehow.

A faint, golden glow radiated from Cassian's free hand, washing over him like the warmth of a distant sun. He extended his senses outward, seeking any trace of fiendish, undead, or other unnatural presence that might lurk within. As the spell settled over the room, the paladin's sacred light revealed nothing amiss — no malevolence, no lingering aura of corruption.

"N-nothing," Cassian reports in slight disbelief as he steps back from the door, ironically feeling even more unnerved now, "No malevolence, just...emptiness. I think that's all w-we need to know. I'm ready to move on when you all are."

Nature: 3!

Chromir will go to the wall and pick up a broken bit of shelving (if there is no broken shelving, he will make some of it broken) and chuck it in the well to see if anything happens to it or if he hears a splash

Chromir strode boldly into the room, the goliath's heavy footfalls breaking the eerie silence. Dust swirled in his wake as he crossed to the shelving along the far wall, his sharp eyes catching a dull gleam beneath the grime. Brushing aside the filth, he revealed a fair assortment of silver plates and platters!

Behind him, the room seemed to hold its breath. From the dark mouth of the well — in full view of the others — a glistening, shapeless mass began to rise, its surface undulating in near silence. The faint light caught its semi-translucent form, sickly hues of orange and yellow, as it oozed upward, a predator unseen and unheard by its prey.

From the doorway, the rest of the party's eyes widened in alarm as the monstrous ooze loomed over its unsuspecting target.  Its movement was dreadfully slow but deliberate, like a coiled serpent about to strike.

The barbarian, intent on the silver treasures before him, was oblivious to the immediate danger.

Roll init!  Chromir will begin this encounter surprised and therefore rolls init with disadvantage. However, the ooze will still go dead last with an init of -1.