Fergus manages to bring Boona back, but she remains prone and incapacitated. (I'll hold Boona's post #3990 until the top of the next round unless circumstances change.)
Striking at the cornered goblin, the goblin immediately reacts by raising a shimmering psionic shield of pure-thought-turned-force, and Fergus' blow is deflected.

Bryony: make that DC13 INT save. (On a fail, take 15 psychic damage and become incapacitated until the end of the goblin’s next turn. On a success, take half damage only.)

Jorzu creates a pretty good replica of Jurgen in the hallway. Jorzu senses that Laiti, still invisible, has returned nearby. ("'Command'? Really?")

Jurgen, Quinn, and Bryony (if not incapacitated or down) may act!

Jurgen, seeing his comrades down, fires 4 (2nd level Magic Missile)  17 Damage.

He moves 30' closer to the action.

Jurgen blasts a quartet of glowing darts at the last fighting goblin cornered on the far side of the mess hall. They all hit. It's in very bad shape but still fighting. Jurgen advances to just behind Bryony.

Quinn and Bryony (if not incapacitated or down) may act!

Int Save - 8

The psychic blast overwhelms Bryony, and she clutches her head, wincing with pain. The pain is so all-consuming that she can do nothing else until it subsides. She doesn't even notice Boona crashing to the ground or Fergus healing her.

Quinn climbs up atop one of the tables to get line of sight of the cornered goblin. Quinn glares at it and marks it as his prey. He grabs two darts and flings them at the goblin.

Bonus Action: Transfer Hunter's Mark to the goblin.

Attack 1: 24 to hit for 13 damage (6 + 3 colossus slayer + 4 Hunter's Mark)

Attack 2: 9 to hit (miss I'm assuming)