Day 1

Anguis, the info that Bellow gives you trigger following: you remember rock gnome master showing you tomb like this. He arrogantly explained that protection of the central part and main entrance are made by real masters - rock gnomes. The backdoors and retreating paths are made by forest folk: forest gnomes and goblins. Bellow - only you see the the corridor ends with huge double doors, approximately in the middle of the corridor you see wide ladders with monuments on both sides. As you share this information you are all guessing this could be the central part of the tomb, while the large doors - main entrance.

Also, please confirm you are all walking down the long hall G. Now as the corridor is wide enough to make formation - let me know what is the formation - do you all keep behind Bellow who have proven to be lucky to avoid traps, does anyone try to keep next, anyone keep distance?

As we move Anguis begins to murmur the quoted information, loudly enough for his companions to hear, as if questioning, where has he gained such knowledge..

Adding at the end...
Whelp, like it or not we're stuck together in this predicament until we get out, so i would rather keep a single team, as you clearly know this place is not exactly safe, furthermore nobody likes parting with the deceased and new people are slow to trust ..... So i believe that we should set some grounding based on at least minimum trust. A name is a good start.
Sorrow and experience are clear in his eyes.

Bellow touches just another floor block and (though the block do not move) it - the block emits a message:
Intruder alert! State your name and purpose!
You also hear strange sounds from the ceiling, raise your heads and notice several (4) tiny creatures that looks like spiders moving from ceiling crawling toward Bellow - two moves by the left wall and two more by the right. It sound like they are mechanical.

OK. Everyone roll initiative. And explain your actions on the first round. That includes Anguis - as he says My name is he see Bellow preparing his axes for a swing. Bubbles - you decide if Anuis continue his speech, but you can say no more than about 10 words per round.

Spiders are on the walls 10 ft above you (15 above )

Gnellson, Bubbles: please describe your turn as in combat.
For example, am I right that that Anguis moves west and do dodge action, while Bellow moves east-north and do prepare action .

You're spot on!

Even before floor end to emit the message, Bellow rise, taking out his both axes and you all know what does int mean if barbarian draw his weapons. Anguis is first to react, stepping left. Phoenix stands still casting a flaming Sphere and you see how it moves up and bumps into a spider. The sphere illuminate the ceiling and you see 4 small holes in it and new spiders crawling out of the holes, while first 4 continue their way dow.
Bellow surprised by bright light delays just a second for spiders to approach him
Spiders one the left however moves toward Anguis, but you see only one of the them and the burning reming of the other on the floor just below sphere (this one is dead)
Spider do not attack as they were dashing.

Now, in the bright light of flaming sphere you see that those spiders are nothing but constructs with a pincer in place of mouth and no ayes. As two spiders approaching Bellow Are running on the floor you hear multiple dissonant voices
Intruder alert! State your name and purpose!
Intruder alert! State your name and purpose!
Intruder alert! State your name and purpose!
Intruder alert! State your name and purpose!
You realise it is the same message with with a different delays, like a multiple echoes but at the same volume. It does not have any magical impact on you, but feeling is very weird.

Bellow lands two axes on the same construct and and it splits in two pieces, Elrond's crossbow bolt hits another, but it is still standing.
Your next turn please
Initiative order: Anguis, Phoenix, "Spiders", Bellow, Elrond