What comes to mind of Rayce from her rolls is nothing particular about the nature of undead bodies, but something like ghost if were to encounter might be hard to kill because of lack of such body. Other than that it might not be a surprise to meet some beasts that prefer dark and gloomy places to live in, assuming they have a way to avoid walking corpses.

As for dwarven archaeologists that Progo was wondering, they have their hands full in the temple for now thanks to you. They might be interested but at later time and definetly only after it is cleared.

Quote from Wakharashq >>

You wake up a little later than usual, after all you were throwing rocks almost all day yesterday. It is still early when you get on your way. After a 2 hours stroll you see the base of the mountain. Thrust out from the base of a dark gray mountain is the entrance to the dwarven fortress — a dark, fifteen-foot-wide passageway flanked by forty-foot-high bulwarks of smooth, seamless stone. An iron portcullis covered with rust blocks the entrance. Arrow slits carved into the bulwarks are dark, revealing no hint of occupation.

Once arrived, Goraseth talks to his commarades. "Let me check the front door. Meanwhile some of you can check around if you see another entrance ? What do you think ?". The dragonborn then approaches slowly the portcullis to investigate if he could see a entry point. Shields up, he is ready for an attack coming from the arrowslits.

Tharanau tells Goraseth:" Stay to the side, I'll produce a little distraction."

He pulls out the wand that he had found earlier in their adventures. He weaves the magic into the air and a harmless burst of multicolored light explodes at a point you can see up to 60 feet away. The burst of light is accompanied by a crackling noise that can be heard up to 300 feet away. The light is as bright as a torch flame but lasts only a second.

He assumes that Seth will not approach straight on but from the left side, so he aims the explosion towards the right side of the building to force a response if it is occupied. If he deems it helpful, he will unload another charge or two. 

Goraseth sees that there is a chamber behind closed portcullis, not lit. There seem to be big doors at the end of that chamber.

Tharanau roll for perception. and i guess anyone who would expect a reaction from a fireworks can do one too. /rather common idea after such display :P/

Rayce rolled an 8 on perception.

She is distracted by the loud noise and concentrates on making an illusion of a group of 3 dwarves climbing the walls to provide further distraction.

She will also do her best to find cover and keep out of sight.

Rolled stealth 21

Is there a way to open the portecullis ? Any lever that we can reach ?

None that you would see outside, and it is rather dark beyond portcullis. (This dungeon Has second floor) the portcullis won't budge event if you would try to fotce it open.

Any opening large enough on the second floor to enter if we climb ?

Tryn observes the face of the dwarfen fortress and looks specifically if he can fit through the arrow slits, or any other openings. 

Arrow slits looks like someone small (like Tryncaryn) could squeeze trough. there are two one the west and one on the east. 

"I could try to get in through the arrow slits," observes Tryn (How high a climb it would be?). "I hope nothing waits in there, though. Alone I won't hold out for long."

"Yes, I don't like the idea of you going alone in there Tryn. I know you can fight but what if you are outnumbered? I don't think any of us knows how to make you invisible by magic?"." Goraseth looks of both side of the entrance and adds "Should we look around for hidden passage ? Every stronghold have secret passage, no ? If nothing comes up, then you could try to go through the arrowslit"

Perception: 5 (sadly)

not that high, you can get there easy with someone giving you a hand. Goraseth you look around and wander a bit but see no other possible entrances. there are some arrow slits on second floor and that is it. the walls of the axeholm are well cutted and seems impossible climb.

"I could try the wand for a secret entrance," ponders Tryn, "but I really don't think there are any. I can be pretty silent. I can try and have a look. If I see any danger, I'll be back in a heartbeat."

If anyone helps him, Tryn will climb up to the arrow slit and enters silently (Stealth: 15). Then, he will immediately whisper to Goraseth with Message what he sees.

Rayce peers into the darkness beyond the portcullis and through any openings with devil's sight. (120ft)

Perception 18

Tryncaryn squezzes trough one of the slits, When he is on another side he stumbles on some heavy machinery, it is slightly visible from little light that comes trough the slit and it looks like big balista set to be shot trough slits. Other than that it is dark and Tryncaryn finds himself in dark silent room.

Rayce sees a room behind the portcullis, there are murder holes on the ceiling that can be used to attack trapped assailants from above (or pour hot oil on them) some more arrow slits on the walls, and big wooden double doors reinforced with iron bars. Rayce also listen carefully and can hear overlapping groans that seem to come from behind the big double doors. Those groans seems to slowly accumulate over time. /Rayce han see Try trough arrow slits with her darkvision but Try stands mostly in the dark./

Tryn remains silent and listens. He tries to find out if anything is moving near him or towards him. Then, he whispers to each in the group if they have some way to make light in the room behind the arrow slits as he can't hide well if he carries a torch. 

Tryn does not hear anything in the chamber he is in

Goraseth replies to the message ans tell Tryn to wait in a corner. He then lights up a torch and throws it throught the arrow slit

Tryn does as advised and moves to the far side of the room(upper left, sorry don’t have the pc for aboveVTT).