Jurgen says to Boona "Well done. I think that will stop him for now, but just to make sure we'll lock him up in here."

She scoops up the skull fragments and brings them over...

"That works," says Bryony. "Although I think it would be more fun to feed it to the octopus."

The halfling starts examining the corpses, looking to see if any of them have anything interesting. 

Investigation - 3

Ruven examines the wheel, bellows, and furnace, seeing if he can determine how they worked while sketching it in his notes.

Investigation: 25

The complex furnace for smelting ore is long-dormant, covered in dirt and rust, but there are still heavy iron doors that open wide and seal closed.

The corpses have nothing on them except scraps of worthless armor.

Ruven takes notes. The furnace is probably functional – or at least salvageable with a little work. 

Unless you choose otherwise, Boona and Jurgen dump the crushed remains of the flameskull into the furnace and shut and lock its iron door.

Everyone but Boona has taken a short rest.

The fire on the waterwheel (from the fireball) is out, but not without some damage to the wheel.

Where to? What next? There are many exits from this cavern.

Ruven will go and mage hand the door to the west. While walking that way, he'll inspect the contraption one last time. No reason to not be able to get this functioning again. I shall return once we have explored the rest of the cave.

Ruven advances toward the western exit, getting his spectral arcane hand in reach of the closed doorway. It budges – but not by much. The 6'x4' door, made of sturdy slabs of stone fitted with iron handles and hinges, must be jammed, blocked, or barricaded by something on the other side.

Hmmm...Ruven steps a little closer to the door, seeing if he can tell what's blocking it. Say, there, Boona, would you mind seeing about broaching this door? I believe it requires someone of your particular faculties.

Quinn walks over to inspect the door first. He looks around for any symbols or inscriptions. He then knocks the stone slab with his mace and then waits for any response. 

After placing the skull bits within the furnace as instructed Boona closed it and walked over to the door waiting until Quinn inspected it still turning over the phrase ' party colour fack alltys ' in her mind.

( If needed- Athletics- 26 )

Quinn whacks the door with his glowing mace. A dull boom echoes through the cavern. The door seems absent of any markings.

Then Boona, in an effortless display of pure muscle, slowly pushes the door in. It was blockaded by the ruins of a massive table, heaped with stones and rubble.

On the other side is what appears to be an old miners' barrack, cut from hewn stone, about 30' by 50' in size. Another door is visible on the far western wall. Old stone bunks line the walls of these quarters, which are lit and heated by a glowing iron brazier in the middle of the room. Six bugbears, including one larger than the others, stand ready in the middle of the room, with six sharp javelins hefted and prepared to throw.

"Who are you? Who sent you?" grunts the largest one. "You don't look dead. Yet." 

Jurgen lowers his weapon and says in a calm voice, "A dwarf named Gundren Rockseeker hired us. Why are you here in this mine?"

Bryony stays behind Jurgen but peers around him to look at the bugbears. She remains wary as the last bugbear they encountered was pretty awful. Her hands twitch toward her blades, but she waits to see how the bugbears will respond.

Amongst the others with their weapons at the ready, Ruven quietly prepares to cast the debilitating laughter spell on the biggest bugbear at the first sign of violence.

"Rockseekers," grunts the big bugbear with satisfaction, and gestures to its comrades. Javelins fly.

Roll initiative! I'll give both the head bugbear and Ruven advantage on the initiative rolls.

Big bugbear: 15
Other bugbears:  20

The closest bugbears are 25' from the doorway, but the first 10' are difficult terrain (the barricade.)
The big bugbear is 35' from the doorway.
Boona, on the front lines, makes an obvious target, but Jurgen is also in front.

Jurgen Init: 20

Init: 21 

Ready for the violence, Ruven enters into bladesong and his movements seem to become even more fluid. He whirls into the room with his blade now in his hand, stopping next to the nearest bugbear while releasing the laughter spell he was brewing at the big bugbear in the back, along with another bugbear in the back near the big one (level 2 slot).

The bugbears need to make a DC 14 Wis save

Boona Initiative- 5

try again- 10