"About to...?"  Ember mutters she hurriedly stuffs her gear into her pack & runs.  

Artan never unpacked anything, even sleeping holding his staff just in case it was all a trap. So he is up on his feet and ready before the cloaked figure enters. He will immediately follow, but will never get closer than 10ft of the cloaked figure. At the same time, he is keeping an eye out for Demetrius

As the Party makes their way out of the room, following behind the Cloaked Figure. Though some (READ: all) of you are suspicious of this person, they seem to know what they are doing and where to go, and if their Master can really help you with this chaos, then it's worth a shot to follow them

As you rush down the stairs, which used to be a spiral that led down for almost three stories, you now find they plateau into a medium sized room. Furniture dots the room,  coaches and tables, as well as a few chairs. The remnants of a fire settle in the brick fireplace, coals still glowing with heat.

In the middle of the room, atop a plush rug, sits an old, birch table, the work of an inexperienced craftsman, from the look of the rough edges and the shoddy craftsmanship. On top of the table is a small object. Closer inspection reveals it to be a small, leather-bound book, with ink stains on the cover

What do you do?

(Is this like we saw a room beyond the stars on the way up but didn't look further at it, or the house layout changed overnight?   Is "plateau" used in the context "stops at this floor"?  Does the cloaked man keep running or look like he's about to go to the table?  

Ember makes a perception check: 24

In addition to the title of the small book on the table, she's looking for anything that could identify the occupants of the tower or their Master.  Address, Letters, Coat-of-Arms, Portraits. Anything she could use with her background feature of "Name Dropping" (You know and have met any number of powerful people across the land) as a History (?) roll to identify them.  She'll roll when she's seen more of the house.

She might try to grab the book, depending on the title

(I have the same question so will wait for a response as it will affect how Artan reacts)

This room is completely new to you. it appears the layout of the house has changed. plateau is used in the context "stops at this floor". 

The Cloaked Figure stops, and looks around, then groans to themself. With a sigh of exasperation, they pull a book from the depths of their cloak, and begin fliiping through it, looking for something. Ember notices that the cover of the book appears to be made of some strange pale material rather than leather.

Ember looks around at the room, and her eyes catch something odd. She shakes it off, chalking it up as her eyes playing tricks on her, but for a second she swears the walls are...pulsing? Ebbing in and out ever so slightly, as if the room is...breathing? No, no, that can't be possible. She must be tired.

As she approaches the book, Ember sees it has no title. A small watermark in the bottom left corner of the cover shows the symbol of a green, grasping hand, reminding you of similar imagery you have seen throughout the tower.

Artan is left shocked by the change. "Does the way we came in yesterday still exist? Or is Demetrius as good as dead?"

Artan can read lips (due to observant feat) so if the figure is mumbling to themselves with words, he is attempting to read them. I am also assuming that based on a 23 Passive Perception, he has noticed the book and the pulsing room, so is getting uncomfortable). "And please tell me that your book is not bound in skin"

(until the next long rest, his reaction thing mentioned in the OOC thread is "Woe (odd). Whenever a creature you can see within 30 feet of you is about to make an attack roll, a saving throw, or an ability check, you can use your reaction to roll a d6 and subtract the number rolled from the total. Three times per LR")

You cannot see the lips of the Cloaked Figure. their whole face is shrouded in shadow. And he also notices the pulsing room

The Cloaked Figure looks up at the mention of a book bound in skin "What? Why would my book be bound in skin. It's a normal book" With that, they slip the book back into their robes.

To be clear, the book on the table is normal, the book the Cloaked Figure was holding was weird.

"And your dad did not try to kill us. Clearly you are a chip off the old block. No wonder the tavern was a cannibal central. What is it? An unfortunate traveller now decorates your book? A gift from your dad or you skin them yourself?"

Artan has not woken up in a good mood today, his usually cheerful self replaced by scathing comments, probably due to the fact that this person's dad made him hurt his new friends, and cost the life of another one and this person is doing nothing that gains his trust.

Wow.

Nat 20 on history roll to identify the history of the green grasping hand symbol & this family

"I swear I didn't know my dad would do that. He's not like that. And now he's dead. Why? Because you killed him." With that, the Cloaked Figure, who is equally grumpy as Artan, begins to make his way towards the only exit from the room: A door tucked into the corner that you didn't notice at first

Ember thinks for a second, trying to remember anything about this green hand. What's that saying 'green with envy'? maybe the hand is envious? No...maybe the hand symbolises envy? And that's why it's green? That must be it

"Can we agree that whoever MADE your dad do that is the real villain here?  At least till we get outside."

Suspecting the guy may try to strand us in this room, Ember picks up the pace to make sure she's in range to dash through the door when he hopens it, if she has to.

Artan turns to the party members. "I don't think any of us will be surprised when he suddenly tries to kill us, but just in case there is any doubt, notice that he didn't deny the book being covered in skin from someone who visited the tavern. Nor did he try and present proof that it isn't skin"

"Not that I trust anyone but he did say it's a normal book.  But the house seems to be breathing, leading to the possibility that the buildings are eating people instead of cannibals.  Let's get out of here before the house eats us, alright?"

Wow. Can't believe no one touched the book

The Party follows the Cloaked Figure out of room, continuing into a long hallway. Which, if you think about it, should be impossible, considering you're in a tower that has maybe a 20 or 30ft radius from the center, and yet the hallway is 70ft long. 

The Party continues past potted plants and portraits hanging on the walls of stuffy nobles, all elves. The strange thing is, you notice, is that every single elf has a tattoo, a twisting, twirling design that curls across the shoulders and neck. Beshlog swears he has seen the tattoo before, but he can't remember where. Travel and stress are messing with his memory. he can't wait for the day that he gets to rest in a nice soft bed.

As you walk past countless portraits, the hallway eventually ends in a door. The door is simple, made of birch, and a lock is set into it.

(Touching a book in a place where everything wants to kill us. I am not that stupid.)

Artan has a think back to see if he recognises that tattoo being on either the grey man (before transforming), or any brief glimpse on the cloaked figure. Also, if the cloaked figure has elf pointed ears from the few times the hood has been down.

The tattoo was in fact on the Grey Man, and maybe it was on the Cloaked Figure too, Artan can't quite remember

Out of curiosity, what clothing is Beshlog wearing?

(I don't need Admiral Akbar to tell me an out of place book on an out of place table in a breathing house is a trap.  And if a nat 20 just gives "envy hand", there's just no point in rolling.)

Ember keeps following the cloaked guy

Beshlog is wearing a set of common cloths, with a (smoldering) studded leather vest protecting his chest. He's also wearing a simple pale-blue cloak.

The giant sighs at the snide comments from Artan and the Cloaked Figure...

"You know, I might not have a great track record with figuring out who not to trust... but... if this guy wanted to kill us, it would have made a lot more sense for him to do it when we were fighting his father rather than after the fight ended."

Having said that, he is content to remain silent, contemplating on where in the Nine Hells he might have seen this weird symbol.

Arthur: True. Though opening it would have provided more clues

Whisker: Got it. Never mind then. We'll see if this is revealed later

Do you try to open the door? Keep in mind it is locked, so you'll have to find another way, since none of you can picks locks