"Hmmm... this inscription. Could it be a riddle? Or is it an epitaph for whoever is inside the sarcophagus?"

Much like Grugga, Leelan ponders about the inscription. He tries to remember if something about "the great shaper" part would evoke something in the history of Amnifortis of the empire as a whole.

History: 10

((So, I think the Cornerstone must be a metaphor. Actual cornerstones are often subject to ceremony, but the dedication is usually written on the stone itself. DM said that minotaurs were common motifs among early human settlers on this content... I wonder if this is the tomb of the first king of Amnifortis? Or at least a dedication to him after the fact. The first king would be a metaphorical cornerstone, setting the foundation of the kingdom/future empire.))

History check to see if Grugga knows who the first king of Amnifortis was: 13 (rolled in game log)

Additionally, Grugga would like to ty to piece together the shattered cermanic decoration to try to get some clue of what we're looking at here.

Rohuzar, the piles of rubble have been smashed to pieces, but based on a few of the larger chunks, they look to have once been statues.  There is an intact forearm and elbow, and several intact feet (inside stone carved sandals) that suggest these were human statues, roughly the size of normal men and women.  They were pulverized, most likely by the Death Kiss.

Raqisat, inspecting the door you don't immediately notice any traps.  As far as a lock, the door was deformed and damaged by the attacking beholder.  It's still upright and in place, but the handles have been smashed and the area where the doors meet (it is two half-doors that meet in the middle) had been deformed and bent.  If there is a lock at all, you would need some tools like a crowbar and a hammer to bend back the warped metal and get access to the mechanism.  Getting through this door may be a small construction project.

[If you want to get through, I suggest the party propose ideas on how to breach this heavy and mangled door.]

Leelan and Grugga, your studies didn't teach you much on this subject.  The majority of the oldest history books come from the Second Empire.  Of the First Empire, most of the hard, historical records were lost in the dark ages between the fall of the First Empire and rise of the Second.  What remains are oral traditions which were then copied down again during the Second Empire once culture and reason returned to the lands.  The Common histories tell that there were no Kings in those days.  The great cities like Amnifortis were said to be ruled by councils of powerful families; the warriors and wizards - and their descendants - who had defeated the Dwarves and secured dominion over the continent.  The stories speak of them like demi-gods, great heroes who were orders of magnitude greater than common men and women.  An Emperor ruled over all these families from the old seat in the city of Viktoris.  It was the Second Empire and Third Empires that saw each city ruled over by Kings [Amnifortis' rulers, the Masitieri's, chose to call the head of the family 'Prince' instead of King].  Still, Grugga would probably still feel good about his metaphor idea.  Unless the 'cornerstone' is a living rock, the epitaph does seem to be talking about a person, not a stone.

(Two half doors that meet in the middle that open like normal doors of that move up and down?  I assume normal doors but...)

     Crowbar and hammer in hand, Raqisat curses colorfully under his breath.  "This is more about destruction than infiltration," he notes aloud to whoever nearby is listening.  "The creatures brute force has all but ensured that it will take more brute force to get through this door.  I did not bring explosives or a battering ram so... I am afraid there is little I can do here."

((Heavy thieves tools mentioned in chat are not known to Raqisat so he has no clue if what they have would be helpful or not...))

Aubrey too ponders the inscription while others work to open the steel door.
History: 15
Another roll if advantage due to history of Amnifortis arguably being a specialized area in Aubrey's studies: 19

((Perhaps Grugga's or Leelan's musings would count as a help action for Aubrey, if it's OK with DM.))

((Raqisat, Grugga would happily tell you about the heavy theives' tools, assuming that we have them... they might be on the boat. DM, would we have those on us? I don't think we explicitly said it, but if they're relatively small enough I think we'd be packing them for any and every excursion))

Rohuzar will get to work helping Raqisat with the tools. 

[While I don't see it specifically spelled out, I envisioned the heavy thieves tool set consisting of all the items outlined on the discord, inside a thick leather satchel and weighing about 40 lbs.  Its probably the kind of thing that would be carried with intention, not 'just in case.'  However, I didn't ask, and its not on the list of stuff on discord that you always leave on the boat, so in my boundless generosity I will assume someone is carrying this stuff with you.]

Raqisat begins the process of trying to break into the heavy door, with Rohuzar lending his strength and another set of hands.

[Raqisat:  Make a STR check.  If you have proficiency in Thieves Tools, you can add your proficiency bonus.  You can also take advantage from Rohuzar's help.  The result of this roll will determine if you are able to breach the door, and if so, how many hours it takes.]

Putting your heads together while they work, the rest of you aren't able to make much more sense out of the inscription.  You will have to hope the answers lie beyond.

Grugga, puzzling over the broken tiles, its a huge mess.  As best you can tell, it looks like it was a vast horde of grey figures surrounding a much larger grey figure.

     "I was wondering what this that was being lugged around everywhere was," Raqisat says when he is introduced to the heavy thieves tools.  "These could come in very handy..."  Examining the equipment brought and considering the door Raqisat eventually takes out some of the tooks and sets about seeing if he can force the door or not.

     "Here, Rohuzar, an assist please?" Raqisat calls out.  "I think if you could hold and shift this as I try to force this part..." Raqisat points out what he thinks will be the best way to force their way through and how best to accomplish it.

((Str+Prof w/advantage: 9 or 17 + 3 for a 20)) 

Grugga holds a lit pebble over Raqisat's shoulder so he can see what he's doing with the heavy tools. "I can't make heads of tails of what used to be here. Statues in strange places and gray-on-gray murals. I'm no expert in early empire art, but this whole things feels... off. Just be careful about traps, is all..."

As soon as Raqisat and Rohuzar are through with the locked door, Leelan would channel a bit of magic to enhance his visions and reveal any traps in the room.

(As soon as the door is open, he peaks in and casts find traps)

Rohuzar is glad he's got an expert to help middle through using the tools, and can just provide leverage. He leans in and finds his feet braced to the floor well as he pushes/pulls as needed

The work is long and frustrating, and involves at least one pinched thumb.  It takes a full two hours of pulling, prying, drilling and hammering to break the lock and loosen the door [it is indeed two side-by-side doors, not over-under doors].  Finally, with Rohuzar leaning on the heavy pry bay, Raqisat is able to wrench one of the doors open.  The other, almost mockingly, swings open gently with the other out of the way.

In the light from Raqisat's lantern and the darkvision of the rest, you see a 25x25 room dominated by a 10' tall marble statue of a minotaur against the far wall.  Yellow stones are mounted in all of the walls hallway between floor and ceiling and there are closed stone doors leading to the left and to the right.

As Leelan pokes his head in to cast his spell, the yellow stones begin to blink in unison.  A flat-toned, disembodied voice speaks loudly in Old Imperial:

 The sound repeats until Leelan pulls his head back out of the room, and then both the voice and the blinking of the lights cease.

Leelan:

"Did you see anything in there, Leelan?" Grugga inquires. "You and Furvus were the first in at least 100 years to look into this tomb... imagine the history here. I hope it's from the first empire." Grugga balls his hands into fists in anticipation and tries to peek at some of the art in the room without actually going inside. "Well done on the doors, by the way. I'm glad we got those tools from the emperor. These descendants and the Underking are going to know we've been up to something down here now, though - that took a while to chew through the doors. Unless we can convince the it took that long for us to set a trap for the Death Kiss, I think we might have to tell them what we've been up to."

"That would be the word alarm repeated in Old Imperial." The young noble says stepping closer to the rest of the team as the door is forced open. "We must expect this place to be magically protected." He adds warily.

As Leelan pulls back his head from the chamber, he massages his temples as if he suddenly had a migraine. Once he comes back to his senses, he turns to his party to reveal what he’s discovered.

"As expected, this room is full of dangerous traps, both magical and mechanical. Apart from the alarm trap that we are already aware of, I believe there may be a trap somewhere that closes and seal the room to prevent intruders from escaping. Then, there seems to be a powerful magical trap of the transmutation variety, I can’t say for certain what it is. Finally, I sense a magical glyph that’ll summon a cloud of deadly poisonous gas. Unfortunately, I can’t quite tell where each trap triggers are located in the chamber. Apologies."

"Absolutely no apologies needed my friend, that was already crucial information to our survival." Aubrey says, giving Leelan and appreciative pat on the shoulder. "I'm not sure how we should proceed, maybe this chamber is too dangerous for us to explore at this point." He continues, looking around at the others in the team.

     Raqisat looks into the room from his vantage point and considers for a moment.  "Magic can be tricky but maybe it can be tricked?" he thinks aloud.  "We could chuck the eye-thing into the room and duck for cover while the room does what it does.  Or if it needs something still alive... The thing was feeding on something, I suppose."