Time to get to work

Carefully Rervenn scans the door for any helpful designs or signs of traps, then looks through the keyhole to get a peek at the other side. Other than some of her friends, she doesn't need to rely on light sources to find her way.

Staying close by the dark knights side, the haregon keeps his glamour up for the next hour. If there is something invisible around, he has a good chance to see it. "Maybe, we want to go up and look what there can be found?" Melang suggests to the others. So many doors? This stinks of traps. Still with the feeling of beeing watched, the fighter itches to see what they are up against.

Rervenn finds a locked door, with no visible traps, through the keyhole she only sees darkness

Go up? If you see that way I could assist. The Dark Knight whistle quietly and in a moment Griffon appears through the doors we all came through. You previously saw that griffon - it is Dark Knight's mount. Griffon come to Dark Knight, get down to help Dark Knight mount it stand up but don't hurry to fly just yet.
The Dark Knight continues But aren't we tasked to go down instead? Should the dark forces approach us from the ceiling I will be able to reach them. Meanwhile -
anyone could guess which doors the previous party took? Let's check if any doors are open - I can't see the end of the chamber, maybe there are the open doors?
The Dark Knight orders his mount to walk through the chamber (North) and would stop if he see any doors open or any sign of any doors been opened lately. This time at normal speed (30 foot walking speed of my mount).

Rervenn proceeds to check out her side of the room as well and inspects the second door in a similar fashion. Locked again? "After securing the ground level, I'd like to see what ate the flying mongrel, first. If there are hostile creatures above, let's deal with them now and see what exactly our permanently indisposed predecessors did up there." Melang has mentioned some gear and rope, who knows what else they might find.

After a peek through the second keyhole, Rervenn goes further north keeping up with the knight and the others.

Rervenn examins the keyhole door by door, untill she gets to a door, where the quality of the darkness is different, deeper somehow.

"The group before us - they left something on this pillar." Melang points in the right direction. "Maybe they were on to something?"

Looking in the direction of Rervenn, he glances back at the Dark Knigh and nods in the direction of the exploring elf. Still looking around carefully the harengon walks next to the pale elf and would assist her in making further investigations. "Have you found something?"

With a piece of chalk the fighter marks the door with a small sign and takes a look through the keyhole himself. "Do we wanna queck the others first, perhaps we find another one like this?"

I don't want to change what my PC does, he is mounted and
he moves until he saw whole chamber, given 60 feet darkvision it would most probably mean just behind the north-most column. Or until something happens of course.

second that.

Agreed that we shouldn't leave much down here to our backs when we go check out the walkways above. Too risky. Zankas says, trying to move just enough to keep all of his compatriots in the lit area.

The dark knight walks past the doors and gives each of them a firm push. At the northernmost door on the west side, the door opens at his push, revealing a large room inside. At the northen wall (4c to 4h) bears a 20-foot-square fresco that depicts dwarves battling goblins

Sorry, Rervenn but I have no respect of the dangers we may face here
Dark Knight silently continue pushing all of the other 13 doors, but do not yet go into any one of them.

The Dark Knight finds a total of two doors that are different from the rest. The two leading into the dark room on the westside of the vault

"Best you fly up there, brave TDK, and look at what ate the owl then. Maybe you find the rest of the first party as well. Who knows maybe you even get to smite somthing in the process, oh raucous one." Rervenn taunts the knight.

Entering the room very carefully, looking for traps and hidden enemies, the harengon takes a look at the fresco for a moment. Do they have heard anything about this dungeon under the city? Was this an old dwarven fortress of some prominence?

Looking around Melang discovers a few steps leading deeper into the earth. He keeps looking around for concealed doors just to make sure he doesn't miss anything.

If nothing happens, he returns to the hall where you embarked on your quest a few minutes ago. In the present circumstances he was primed to see what Hamburg had done upstairs. There must be something in the room with them....