Out of Character: Wait a second, seems actually didn't do the Perception roll. One moment as I fix that mistake.
Zarra carefully weaves an illusion over the view hole. The group presses on. Either whomever is on the other side isn't paying attention, or the illusion worked, as no cry of alarm goes up.
Forging on, more traps are found and disabled. Eventually, the trio spot light ahead. They are probably nearing the barracks.
If Amabalus, Tazskan's pseudodragon can also follow the trio, sharing the same invisibility illusion, effect he will follow.
If not, then he will remain behind watching the entrance, staying hidden in a nearby tree.
Mari studies the situation intently. (Zarra, maybe you should turn the two of us invisible. We could stay a short distance ahead of Poljen since we are more practiced in being quiet. Being invisible would enable us to see enemies before they notice us. We would always have Polhen right behind us if we need help. Just an idea.).
Poljen nods at the idea. {We need to keep moving. But if things go bad before we get to the mask, we will fall back to a defensible position until the others can get to us. If we manage to get the mask, then things go bad, I will hold off the enemy while you get the mask out, and hopefully survive until the others can reinforce me.}.
Zarra nods, before providing in her companions' minds, 'Yes, though we may want to fall back just a little bit as I get the spell cast on both Mari and myself.' The drow didn't want anyone to stumble on them as she was using her magic, thus a more concealing place being what she had in mind. Once this was done, they could continue forward with the two woman somewhat ahead.
Mari smiles as she turns invisible. (That will do nicely Zarra. We must beware of the dragon. Remember that invisibility isn't much good up close.) She stalks ahead as silently as she can. Mari will look for traps and for anything that could spot Poljen behind them.
The two invisible scouts at the fore have little trouble slipping by the kobolds in the barracks. Poljen would need to get particularly lucky to do the same. None of them seem to be actually watching the passage, but they're moving around a fair bit, and it is clearly visible from several spots.