“Do not enter this room.  Do you feel the energy in here?  Danger!  I like the idea of trying to open it with your mage hand, as a first effort, if nothing more.”

Eldeth begins uncoiling her rope. "I'm sure the thing's locked. I'm a little worried that she'll have magic prepared for if that book leaves the chamber, but I don't want to take the whole chest without being sure the book is inside, either. Better to at least not have to deal with the lightning, though." Once the rope is uncoiled, she'll summon forth her mage hand again, and have it pick up the middle of the rope, and drag the rope by the middle to put it around the far side of the chest, like a V. She'll keep hold of one end, and hand the other end the Barkas, who at least seems to be acting sensibly. "Here, once the mage hand's got the rope in place, we should be able to just pull." The mage hand is instructed to keep hold of the middle of the rope, and to stay at about mid-height of the chest, to keep the rope from slipping under it.

"It's going to be locked,"  Edrik says rather matter-of-factly.  "But we should try the spell first. See what happens. Maybe it will give us some ideas on how to dodge the sparks."

Matthias would simply smile and chuckle at the banter between his comrades, fairly amused.  "At this point, I'm all for whatever can get the job done.  And if I'm going to be blunt, how in the blue hells is a dragon no-bigger than a cat going to open an iron chest?"  He'd stutter at the end before erupting in chuckles.  "Though in fairness, we don't know how this trap works.  Is it getting within a certain distance from the chest?  Is it touching the chest?  The chest is made of iron so you'll certainly get zapped touching it.  Let's see with the dwarf-squad fairs first."

Faloniir will say, "It seems you all misunderstood me. I merely suggested we send the dragon in the room, not that it should do anything with the chest..."

"Fair, though maybe Elonath can let us know how to traverse this room instead of sending him in, RIGHT?"  He'd give a mischievous smirk at the psuedodragon.  "But in all seriousness, I'd rather not put Elonath in danger.  The Harpers might have use for him and reward us even more."

The mage hand guides the rope around the chest as Eldeth intended; but the moment she and Barkas prepare themselves for pulling on the rope, the undead guardian of this room appears: a specter. Emerging from behind one of the pillars, it hovers over the chest momentarily before flying to the open doorway. Its wrathful countenance falls upon Barkas as it reaches out to drain his life force...

• Life drain attack: 20, causing 11 necrotic damage

(Barkas must now succeed on a DC 10 Constitution saving throw; otherwise, his hit point maximum is reduced by the amount equal to the damage taken. This reduction lasts until he has taken a long rest. If the hit point maximum is reduced to 0, then the individual dies)

All players may act. 

Upon seeing Barkas take the life drain, Saville's eyes would widen in shock.  With as much the specter did, he could have sworn Barkas was dead.   Thinking quick and in a rush, Matthias would lift his bow and take aim, focusing hard on the undead and hoping he can help disrupt its form with arrows.

"Barkas get out of there!"  He'd call out to his ally before flinging an arrow.

Bonus Action to put Favored Foe on the specter.

Longbow Attack:  14   Damage: 7   FF: 4

Faloniir will rush unthinkingly to Barkas' aid, "Someone get him out of there!" as he slashes at the Specter with his scimitars.

Attack: 16 Damage: 10

Attack: 9 Damage: 10

Barkas con saving throw :  20 

Barkas moans “Unngggh!” when he receives the life drain, up unto an inch of his life.  He disengages and moves to the back, facing the specter, breathing hard.  

Eldeth will drop the rope and disengage, running as far away from the specter as she can.

Rasp instinctively drew his blade upon the specter appearing. The thought of needing a semblance of organization crossed Rasp's mind. The tall Kenku strode forth, shield held aloft. His other held his skull-like talisman, now alit with an electric-purple glow, giving the skull the visage of being alit and screaming in horrific pain. The intimidating Kenku stood, tall, cloaked in black-painted armor, cowl, and feather - seeking to draw the Specter's notice, shield prepared to deflect any attempts at attacking. 

"Today you will reach your reckoning, specter. Submit, and your delivery to permanent death shall be swift," a booming voice emanated from the Kenku's mouth; inhuman and reverberating - certainly not one a mortal could pronounce, but one a Kenku could mimic. His patron had given him a few phrases to copy, particularly in moments as dire as this. 

(OOC: Rasp is seeking to draw the Specter's attention and dodge, hoping to prevent the Specter from attacking anyone else. Let me know if you desire any rolls! Persuasion/Intimidation are both equal - 11, if needed.)

Edrik draws his bow and fires a shot at the specter, moving over to check on Barkas. "You survived that! Thanks be to Moradin, let's keep you that way." 
(Attack: 11 Damage: 4)

The specter is struck in quick succession by Matthias's arrow and Faloniir's blades, but both men take notice of the fact that their weapons seem to lack full efficacy against this evil apparition. Edrik's shot narrowly misses, and the arrow flies into the room behind the specter and shatters against the wall. 

As Barkas and Eldeth give themselves some distance from the melee, Rasp steps forward, ensuring the specter's wrath will now fall solely upon him...

• Life drain attack (w/ disadvantage) 21 for 13 necrotic damage

...but the specter's reach fails to touch the kenku.

All players may act.

Matthias sighs in relief seeing the dwarves bail and getting a safe distance.  As the two more physical fighters combat the specter, the hexblood gets right back to business to take this undead creature out.  It may not be a solid creature, but the arrows seem to at least be doing something.

Longbow Attack: 18   Damage:  6   FF:  2

Faloniir will continue to press his attack against the Specter, swinging both scimitars in a flurry of steel.

Attack: 9 Damage: 6

Attack: 25 Damage: 5

Eldeth will move to just behind Matthias where she can see the specter, and strike out with Chill Touch. Attack: 6 Damage: 2

She'll then back up again.

For a second time, Matthias sends an arrow into the specter's form, and, although his first blade misses, Faloniir's off-hand scimitar takes another bite out of the angry undead. As the specter rages and twists in response to its wounds, Eldeth is unable to make contact on the apparition with her spell. 

All can see that the specter--or whatever force it is that drives it--is waning...

Actions for Barkas, Edrik, and Rasp are next.

Edrik mutters under his breath as his first shot misses. He aims his shortbow again, trying to hit the spectre.

(Attack: 11, Damage: 6)

In a carefully timed maneuver, Rasp deflected the specter's blow - the Kenku's striking arm raised, thrusting upwards with his sword as the specter's attack left it wide for a counterstrike. 

Longdsword Attack (I'm unsure if this would be considered Flanking; rolled two dice just in case): 14 Damage: 8