Dungeon of the Mad Mage

You find the drow mages spell book and it contains the following spells that a wizard could copy. 
1st level (4 slots): mage armor, magic missile, shield, witch bolt

2nd level (3 slots): alter self, misty step, web

3rd level (3 slots): fly, lightning bolt

4th level (3 slots): Evard’s black tentacles, greater invisibility

5th level (2 slots): cloudkill

The Quaggoths gesticulate towards the door behind them and open it slowly. Through the door are several pick axes discarded on the floor and what looks like gold veins in the walls. 
“Little slaves collect shinies from wall. Must have run off when they heard big roar. Door on side heads to priestess room. One at the end of room leads to prisoners.”

Eoan gestures to the Quaggoth in appreciation nodding , moving into the room quietly to take a closer look at the veins of metal in the walls then moves quietly to the door to the priestesses room listening with his ear to the door. 

Nature 5

perception 13

As far as you can tell this is gold ore. The troglodytes have chipped off twenty 1-pound chunks

You see a giant spider hiding above in webbing waiting to ambush something it may consider prey 

Whispering to the rest of the group as he keeps an ear to the door . “ looks like payday to me boys !”

Throwing his spear at the spider burning a ki point to stun it (dc15) and cause it to fall 

Attack: 16 Damage: 17

Attack: 13 Damage: 21

The spiders legs curl as it falls from the webbing. It impacts onto the floor with a hollow crunch. Two holes in its carapace leaking ichor onto the flagstones

The bronze relief door stands slightly ajar leading to what the quaggoths called the priestess room. 

Looking around you notice that the three Quaggoths have sloped off while Eoan was despatching the spider. Presumably for slightly less deadly environs 

Religion 3

Religion - 20 

Both Eoan and Jhee-Khar recognise the carvings to be from a dwarven religion to Dumathoin. Some of the pyrite has been rammed into one of the eye sockets unlocking the door. 

Stealth 27

Stealth 19

Slipping silently through the door Eoan and Leo see a drow priestess of Lolth, stands atop a raised dais at the back of the hall, presiding over a group of four drow and three giant spiders. The priestess is berating 4 troglodytes for abandoning the mining. 
Scores of tarantula-sized baby giant spiders creep and crawl throughout the room.
Stone pillars hold up the 30-foot-high arched ceiling, which is concealed by a thick canopy of spiderwebs. Strung between the pillars and bas-relief carvings of towering dwarves protruding from the walls are humanoid corpses cocooned in spider silk.
The back wall of the temple is carved with a towering bas-relief of a mountain. Lashed to the mountain with sticky webs is a struggling and gagged male drow with sacks of spider eggs clinging to his body.

After interpreting some hastily mimed hand signals from Eoan and Leo, Jhee-Kharr runs into the room and punches the first enemy he encounters, then manifests a flaming aura and shoots fire from his fingertips 

Attack: 10 Damage: 7

Attack: 11 Damage: 8 

Burn!!!

15-foot cone. Each creature must make a Dexterity saving throw. A creature takes 11  fire damage on a failed save, or half as much damage on a successful one.

The fire ignites any flammable Objects in the area that aren't being worn or carried.

The flames set alight to the webs lacing the room. The closest drow is beaten to death by Jhee-Khar. 
scores of the tiny spiders are incinerated. The troglodytes are caught in the blast as well. 
Saves for them. 10 4 12 15

Initiative rolls

priestess 8
drow 7
giant spiders 11
troglodytes 12

Sig 14

Initiative 22

Initiative 24

Initiative 8