Wilmot follows the others up the stairs, doing his best to try not to make them creak. However, he's a big guy and wearing a lot of armor. It's not the easiest of tasks. "Oh, dear me, this is quite the tight fit," he mutters, scraping his shoulders and shield along the wall as he ascends. 

Stealth (at disadvantage): 12

Gracy holds position in the kitchen, keeping an arrow knocked and ready to respond to anything threatening the group from behind. 

'No use in trying to be quiet at this point, the fight and the alarm should have brought anyone here running.  If they didn't I fear it's because they lie in ambush waiting for us.'

"Good point", Archibald says and begins to walk up the stairs carefully  behind Klaus but not worrying too much about being stealthy.

AREA 13 - GUEST BEDROOM

This bedroom has no furniture, but rubbish is scattered everywhere, and webs cover the walls and ceiling. From the doorway, you can see a glint of light in the fireplace from a small, highly reflective object.

AREA 14 - CRUMBLING BEDROOM

This room appears to be another dirty, decaying bedroom without furniture. Even viewed from the doorway, it’s evident that the floor in here does not look safe; some of the floorboards are missing, and others are partially dislodged.

DC 10 Intelligence (Investigation) or Wisdom (Survival) check: ?!?!?!?

AREA 15 - RUINED BEDROOM

DC 10 Wisdom (Perception) check: !??!?!

Wilmot carefully taps the floorboards in the crumbling bedroom, moving slowly to inspect the room. "I think it will hold me...." he mutters, clasping his holy symbol and asking for a bit of guidance as he moves in.

Survival: 25 + Guidance: 3

Gracy carefully peers around the corner into the crumbling bedroom (A14), checking for traps, hazards or any signs of the people who must be bunking in the cellar of this house. 'Oy, Archie, lend me that spectral hand of yours, clear out some of the crap over in that corner so we can check it without going in there yet'

Investigation with help from Archie 19

Wilmot/Gracy, or anyone who passes as well, successfully spots the weakened floorboards and does NOT go falling through them, crashing to the ground. Excellent! You also detect recent tracks that lead from the door to the window, and back again, along the west edge of the room. 

DC 12 Intelligence (Investigation) check from you now: ?!?!?!?

Oh, Gracy made one. Here:

There are fresh scratches on the sill where a signaling lantern might have been placed, scuffing of the floor dust immediately near the window, and so forth. This is where whoever is signaling something. Most likely a ship.

Zmeya points out the weaker boards in the staircase and floor, indicating that the more heavy of the group should avoid stepping inside unless necessary.

Doesn't look like a Perception check for Area 15 was made, so here it is - 16

Zmeya, you spot numerous weak floorboards that, if anyone were to step on them, would plummet to the ground floor if stepped on. The upper floor of the mansion, in certain parts, it seems, appears unstable.

Hiramat will join his companions up the stairs, he watches for the floorboards that Zmeya indicates to avoid falling through.

Klaus moves along with the group, mindful of the spots indicated by Zmeya. He is interested in the reflective object in Area 13. 

The glint inside the fireplace comes from a small crystal bauble. The flat-bottomed crystal orb is pleasant to look at and tactilely satisfying to hold, but ultimately neither particularly valuable nor useful. You can hear the loud buzzing of insects coming from up the fireplace. Oh shit.

FIREBOLT!: Attack: 18 Damage: 10

"Looks like we have trouble. Let's deal with this and leave the vermin control to anyone who wants to move in. I would try to go about this place undisturbed in the future, no matter how shiny the objects seem."

Zmeya readies to throw a sharpened, bone blade from a pocket in one of her sashes if the swarm of insects seems hostile!

Wilmot chuckles, "Looks like we've stepped into the proverbial hornets' nest, no?" Not getting the chuckles he hoped for, the cleric steps back, clutching his holy symbol in case a spell is needed.

While diminished, thanks to the firebolt, the swarm of bugs erupts from the fireplace and attacks everyone in the room with bites and buzzing - causing 1 damage. A total of about twenty more damage will need to be inflicted to kill it. Anyone can attack in any order, but once everyone has gone, you suffer more bites at 1 damage per character in the room until it is defeated.

Zmeya resorts to spinning her staff like a windmill, more annoyed at the creatures than frightened.

Action - Attack: 13 Damage: 5
Bonus Action - Attack: 20 Damage: 7

Hiramat swings his blade side-to-side hoping to cut down some of the swarm before they overwhelm the group.

Attack Longsword Attack: 6 Damage: Unable to parse dice roll.

Damage 7

Firebolt:

Attack: 6 Damage: 4

The insect swarm dissipates, and the buzzing stops. No more damage will be inflicted.