Sure enough, the gate silently creaks open slightly. 

Without a sound, Syvis leans out just enough to get a look around to see if any of their captors are in sight.

Perception: 25

There are no drow anywhere to be seen from your vantage point. 

However, you slowly begin to hear a horrible droning buzz echoing through the cavern, followed by inhuman shrieking. Suddenly, alarm horns sound out as a swarm of large insect and bird like demons fly through the outpost.

Velkynvelve is under attack!

Are the alarms and shrieking coming from everywhere? A particular direction? The direction of the armory? The consort's quarters?

Thodek bows his head in a quick prayer to Moradin, and then starts moving towards the armory as quick as his short little legs will carry him. 

Rian follows Thodek, 

“Luck is on our side, but we must be quick. We don’t want to get caught up in this!”

Cailean coaxes his little spider friend onto his shoulder if it is willing, and moves to leave the cell with the others. "That would qualify as a distraction, wouldn't it," he muses quietly. He eyes the group as he continues a little more loudly, "Most of us I am sure can see fairly well, but if any of you who have difficulty seeing in poor light you are more than welcome to stick close to me. I'll help guide you until we can safely use other means of light without giving ourselves away."

Syvis: The demons are flying around in the large cave that Velkynvelve is built in the side of. Additionally, a short while after the drow alarm sounds, you can see drow soldiers trying to fight the demons off. (They are paying no attention to you.) 

I have updated the map of Velkynvelve, circling the locations of the armory and Shoor’s quarters in red)

Anyone running to the armory needs to make a stealth check with advantage due to the guards being distracted.

Buppido: 10

Prince Derendil: 7

Eldeth: 21

Jimjar: 8

Ront: 6

Sarith: 18

Shuushar: 17

Stool: 10

Topsy and Turvy: 14

(Wow! Good rolls from the NPCs)

"Opportunities abound," Syvis mutters as she follows Thodek and Rian.

Stealth: 23

Cailean falls into step with the others, fingers flexing to warm them up for action.

Stealth: 23

Stealth: 13

Fast on their heels, Nicholas follows the others to the armoury.

Stealth Check with advantage: 7 7

Voyage follows behind, keeping up the rear of the group. Her tail dances with excitement and her golden eyes flash as she watches the demons buzz and fly overhead. "This common down here?" She will ask if she's near any Underdark dwellers as she moves.

Stealth Roll: 18

Thodek stealth: 18

On the way, Thodek, with his superior vision in the dark, will try and make sure their path is clear ahead of them.
Perception: 9

Due to most of the group having very high stealth rolls, you are able to pass through the outpost unnoticed for the 50 feet it takes to reach the armory.

 You enter to see a small and lightly furnished room, coming face to face with two drow soldiers who seem to be on their way to join the battle against the demons.

The group locks eyes with these two soldiers who begin to draw their weapons with a smile.  

Roll initiative!

NPC Initiative: 10

Drow Initiative: 8

Thodek initiative: 6

Rian’s initiative: 20

Nicholas' Initiative: 9

Syvis' initiative: 16