Sadly, only Xerim gets the true meaning of Carina's performance and slightly nods at her, signaling her to be ready for whatever might come. The others cannot quite see what she is doing. Pandora and Elmira are too far away and Ashton is too busy with the elf to even look properly in Carina's direction. 

As Carina looks up, disguised by the branches she had conjured, the platform and the unknown person up on it seems to be about 15 ft. high in the tree.

Xerim also moves into the cover she has created but is not able to see anything, since he cannot look through the illusion yet and Carina could not explain in detail to him which parts of the tree are illusory.

(@Carina - you do not have clear sight on the person. Just the tip of a foot. What are you planning to do?

What are the others planning to do?)

Pandora is still standing by the tree. She would like to go over to Carina, but she can't leave Elmira alone. So the elf continues to stand still and tries to recognize something. 

Since Ashton still doesn't know anything about it, he will push the elf in front of him in the direction of the cart.

The group watches as Ashton and the elf start leaving the tree line and cautiously walk towards the cart on a more direct way. The elf is visibly disturbed by the trap he almost stepped in a minute ago and looks at Ashton with sorrowful eyes, but Ashton does not give it any thought as he watches the tree line and every piece of snow in front of them closely.

( Two things:

First - @Elmira and @Pandora, please give me another Perception check to see if you have realized, that Ashton pulled the elf down because of something he found there.

Second - @Elmira and @Pandora - I would like to try out the new DnD hiding rules, so please give me both a Stealth check with advantage to see how well you are hidden. Remember: Elmira has +1 today on any roll that has to do with stealth, sleight of hand and other skills of thieves.

)

Perception: 17 (with Proficiency Bonus 21 (because of expertise))

Stealth: 8 + 1 = 9

Carina tries to consider her options.  She sees no good way to get the drop on the hidden lurker.

Attack them when all I can see is their foot?  Attack the platform they stand on when I'll likely just have my Eldritch Blast just bounce off it?  All while my companions have no clue what I am trying to do, other than Xerim, whose view is blocked by my Minor Illusion?

Instead she decides to dispense with the stealth, given that Ashton and the elf are out in the open anyway and the sentry at least must have seen it.

She announces to everyone, projecting her voice so all her companions can hear:

"There is a sentry well-hidden in the tree above me, standing on a platform. A humanoid.  There may be others."

She then addresses the hidden humanoid directly.  "Hello, shy one.  What are you doing up there?  Planning to attack or sound an alarm, perhaps?"

(She tries to project confidence.  If no answer, she repeats the question in the other languages she knows - Elvish, Dwarvish, Giant).

With her action, she takes the dodge, with the Minor Illusion also blocking her from view from this sentry at least.

Ashton hears Carina shout and will jerk the elf back off his feet and start to drag him to the closest cover. "Get down, I'll try to cover us."

He spins looking into the tree above Catina.

Perception: 11

Everyone can hear Carina calling out the sentry, so even Pandora and Elmira do know now that someone is hiding in the tree above Carina. The captured elf falls prone into the snow as Ashton is shoving him, while Ashton tries to spot the creature, Carina is talking to, but from his position, he can only see snow covered tree branches. However, he sees Xerim readying his spear and shield.

There is no other response from the sentry than the foot disappearing somewhere on the platform. Whoever is standing there, seems to prefer to pretend, that he has not been spotted.

Quote from Katzenlu >>

Perception: 17 (with Proficiency Bonus 19)

Stealth: 8 + 1 = 9

(@Pandora - Please roll Stealth again, you have advantage.)

Quote from Rubikow >>

Quote from Katzenlu >>

Perception: 17 (with Proficiency Bonus 19)

Stealth: 8 + 1 = 9

(@Pandora - Please roll Stealth again, you have advantage.)

 oh good you say it! Stealth: 23

Hint: i changed the Perception to 21 

Carina Investigation:  12.

On the underside of the platform above her where the humanoid stands, trying to find a weak point where she could break it with an Eldritch Blast.

(She does not do so yet).

Carina can see that the platform supported by wooden braces that hold up the platform. She can see two of them quite clearly under the area where the foot could be seen before.

Carina briefly drops her Minor Illusion and quickly and quietly points Xerim at the wooden braces holding up the platform.

"Be ready to target those and stand clear should it fall," she whispers to the silver dragonborn.

Re-creating her Minor Illusion, Carina speaks to the hidden lurker, an edge in her normally mellifluous voice.  "It is impolite and more than a little creepy to watch us unseen from up in the foliage there.  If you are not an enemy, then give us a way to know that.  Sooner rather than later would be good."

Taking a deep breath, she decides to chance a gambit:  "We seek a cure to the icy blue disease that has sickened several in these frigid lands, including Hulil Lutan there in the cave beyond.  This is bigger than the town or the bandits.  Help us."

(As before, she repeats the message in Elvish and Dwarvish if no response initially.)

"Did you hear that Elmira?" she looks at the other elf. "Sounds like we might be in trouble. I walk over to the tree on our left (i36) to be closer to Carina and Xerim." Pandora looks worried. As she sneaks to the tree, she scans the treetops. If there is one, there might be more.

Perception: 25

Within her range, Pandora cannot see any other strange trees or platforms as she quickly moves, still hidden, to her new position.

Meanwhile Carina does not get a reaction from her attempt to talk to the lurker. However she perceives some movement between the trees nearby.

Ashton grunts at the elf.  "How many are in this group you used to be in?"

The elf looks at Ashton from the ground his eyes moving as he tries to remember things.

"I ... In the town we were 5. B .. but w.. we talked to at least 5 different more and ..."

At this point the elf stops talking and his eyes grow wide as he stares at the feathery end of an arrow, that suddenly blocks his vision as the arrow is sticking in his throat. A second arrow misses Asthon just by an inch ... but intentionally, as it finds the chest of the elf.

Spitting blood, the young elven man grasps the arrow in his throat with a shaking hand in disbelief before he collapses in the snow, his upper body suddenly outlined by a growing red corona.

(Ashton give me an perception check again please, to see where the arrows came from)

While Pandora is focusing on Carina she notice some strange movement from Ashton. Unfortunately, their view of the bandit is obscured by a stone in front of her. "Ashton looks shocked." she whispers to herself. "Oh no! no no no no!" now she's not whispering anymore. "Elmira! I think we are in trouble. Hide yourself and get prepared for a potential fight!" she calls out to the other elf, knowing that there is nobody around them. She presses herself against the tree so as not to let her guard down and reaches for her daggers. I can't run to Ashton. This would be suicide. Join Carina and Xerim? If the bandits were sitting above us in the treetops, we would make an easy target. Crap! Not knowing what is really happening out there, Pandora stays in place for now. 

Carina calls out:  "Movement in the trees.  Unsure if it is the one that was in this tree on the move, or others."

Her mind processes what she is seeing with the arrows killing the elf bandit but none aimed at Ashton (so far, anyway).

Bandits killing their own to shut them up?  Hidden sylvan humanoids killing bandits?  Why did they attack the elf bandit but not us?

Insight:  10