Fergus:

On his turn, Fergus moves and dashes so he can see into the new room, but he stays in the hallway.

(Wanting to be in position to react with Silvery Barbs if Boona gets Crit)

Jorzu 

Initiative 4

Fergus races forward, just outside the door, keeping an eye on Boona.

Jurgen may act. He is just outside the door and still has his movement and action.
Bryony may dash or otherwise act (she is well aware that Boona has just crashed through the barricaded door, but doesn't see anything more.)
Quinn, likewise. But first he should roll initiative (and meet or beat an 8.)
Boona, facing three hostile rock-throwing(?) dead dwarves, may roll initiative. On an 8+, she may advance to try to clobber one of them (she's 15-20' from the closest.)

The once-dwarven blacksmiths' eyes glow with otherworldly power. Their ashen skin is desiccated, but the muscles underneath substantial. Clearly dead, they are not slow.

A sea of blue lava roils slowly outside the windows in a vast cavern.

Jurgen will move through the doorway and to the right, making room for others to enter the room. He then casts Firebolt at the nearest undead (10 to hit with 8 fire damage)

Boona Initiative- 10

Boona Attack: 15 Damage: 13 + Smite 17

Quinn’s initiative: 1 :(

Quinn steps into Ruxithid’s room briefly to look around, but before he has the chance to investigate the room, Boona barrels through the door.

Quinn turns on his heels and runs to see what’s going on.

Move + Dash = 80 ft

OOC: whenever it’s Quinn’s turn, this will be his movement plus action  

Bryony hears the commotion of Boona bashing the door open, and she rushes toward her giant friend in case she needs help. 

Action: Move + Dash - 50 feet

Jurgen steps inside the ancient forge and lobs a mote of fire at the closest dead thing. The dead dwarf is clad in little more than rags and dry skin, but they are quick on their feet and tougher than they look. (10 misses.)

Boona steps forward, ducking under the stationary conveyor of buckets. She swings, but it likewise glances off the dead dwarves' natural armor. (15 also misses.)

Quinn begins to run down the hall. So does Bryony.

The ashen corpses surge toward Boona and Jurgen. One pummels Jurgen with chunks of black rock, another Boona. A third throws fragments of rock at Boona.

Ashen corpse #1:
Necrotic Shard #1 vs: Jurgen. Melee Attack: 9. Hit: 7 necrotic damage, and Jurgen has disadvantage on the next attack roll he makes before the end of his next turn.
Necrotic Shard #2 vs: Jurgen. Melee Attack: 11. Hit: 10 necrotic damage, and Jurgen has disadvantage on the next attack roll he makes...

Ashen corpse #2:
Necrotic Shard #1 vs: Boona. Melee Attack: 26. Hit: 10 necrotic damage, and Boona has disadvantage on the next attack roll she makes before the end of her next turn.
Necrotic Shard #2 vs: Boona. Melee Attack: 24. Hit: 8 necrotic damage, and Boona has disadvantage on the next attack roll she makes...

Ashen corpse #3:
Necrotic Shard #1 vs: Boona. Ranged Attack: 18. Hit: 6 necrotic damage, and Boona has disadvantage on the next attack roll she makes...
Necrotic Shard #2 vs: Boona. Ranged Attack: 19. Hit: 8 necrotic damage, and Boona has disadvantage on the next attack roll she makes...

Quinn sprints forward. (With 80 feet, he can get up into melee with the closest one. Does he want to end his turn there, or stay back with Fergus?)

Jorzu may act!  Then, Jurgen, Boona, Bryony, and Fergus may act.