"I will take each of our blades to the grindstone, so that we may cleave this lord."

(I don't really know what Jorin might be able to do so I'm happy to take suggestions from the group lol)

Quillary looks away from Sarah, to Hildi. “I would survey the Yellowcrest manor, see what I can find. I can do this as a small creature, and go unmolested.”

Sarah has no idea if Jorin understood her Charades or not (post 5244).
Jorin might be able to get useful information from the ghost, but she doesn't know what you want to know.

(If Jorin doesn't want to quiz Sarah, he could go to historical records. If he doesn't like a History check, he can try to Persuade a scholar to do the work for him.)

Drusk offers to Help out someone, since he has proficiency in Religion and History.
(Depends if you want Hildigrim to roll the Arcana check with advantage for those magic circles, as you would be combining arcane and clerical knowledge.
Or Drusk could check the historical records, or work with Jorin on that.)

Quillary has offered to go to the Manor on Delzorin Street in Waterdeep’s North Ward (but I'll wait until the party has made firm plans).

Pascal is busy, since the Bistro is still relatively new, but he will help if you suggest something specific for him to do.

(Oh!  Get someone to do the research for me, that's a great idea.)

Jorin thinks that Lord Yellow crest had cut out her tongue to keep her from talking about the book...either that or cut out her tongue to bind her to the book via foul sorcery.  Is that about right?

Jorin offers to go to the Waterdeep record keepers and attempt to get one of the clerks to do some research on the Yellowcrests by explaining he needs information on the family as it is a matter of extreme importance.  The fate of a ghost, trapped in a book unjustly, hangs in the balance!

He is looking for what the Yellowcrests were into in the year or so leading up to when we think this happened, and anything notable afterwards.  He would also ask about the love interest, Vecken -- who he squired for and if he ever bacame knight.

Persuasion: 16

Quote from Guiltysparc >>

(Jorin thinks that Lord Yellow crest had cut out her tongue to keep her from talking about the book...either that or cut out her tongue to bind her to the book via foul sorcery.  Is that about right?)

When Jorin starts mumbling out loud his thinking, Sarah waves to get his attention back, nodding yes early on, but shaking her head no to all those guesses about the book.
When Jorin looks confused, she points to the book, and mimes reading and flipping pages. (She was previously trying to refer to events described in her diary, but can't touch the book directly.)

Jorin, through either luck or keen observation, is able to find a scholar who is almost obsessed with Waterdeep nobility and true-crime sort of stories. With Jorin speaking so passionately (and cryptically), she is more than eager to share information about the murders.

The public details of the dark event are well known:

• Lord Yellowcrest was away from Waterdeep on business, then returned to find his wife, his sons and daughter, and the manor’s four servants brutally murdered. Shocked into a deep depression by the tragedy, Lord Yellowcrest left Waterdeep to be alone with his grief.
• Rumors seemingly spread by members of the City Guard after investigating the murders hinted at some sort of cult activity, but details of the killings were never revealed. No suspects were ever identified or charged.
• The Yellowcrest family had a good reputation, with no hint of personal or public impropriety. No one ever accused the grieving Lord Yellowcrest of having any connection to the murders.
• For Vecken, he had a reputation for bravery and perseverance. Five years ago, Vecken joined an adventuring company and made a name for himself. A well-known sortie against a bandit lord south of Neverwinter earned him the nickname “Sir Vecken of the Broken Horn,” after his horned helmet was nearly cloven in two during the fight. A year ago, he returned to Waterdeep, and there is no other news about him. The scholar points out that Vecken's father, Yacken, has a house on Immar Street, a few blocks away from the former Yellowcrest Manor.

Drusk will help out Hildigrim. (Advantage on Arcana roll.)

(Mingofaust can choose how things go with Quillary. Her plan was to sneak in to the manor, but the question is, does she find out the Yellowcrests don't live there before or after breaking in? If she was waiting for night, then Jorin would have informed her of the new occupants: the Falgarst family.
If she broke in early, she would notice quickly on entirely new family with a father who does not match the description of Lord Viallis, and that there are no emblems of the Yellowcrest family anywhere in sight. )

No, Quillary was always going to surveil from outside during the day, first, in pigeon form. So she will have figured that out and returned to find and corroborate Jorin’s news. One day down. Next!

Arcana with advantage: 23

QQ about the timing of things...Was Vecken's time in the adventuring company before or after the Yellowcrest murders?

Quillary: While watching the mansion from the outside (and noticing that a new family moved in at some point over the last 5 years), she does recognize the parents from a few days before. When the party is comparing notes later, Pascal will point out that the Falgarst family were among the nobles who attended the Bistro opening.

Jorin: Newspaper articles don't have all the details about Vecken, but the stories about his time with the adventuring company did start shortly after the murders.

Hildigrim: Turns out that he didn't need much help, but Hildigrim won't complain about having someone around to fetch the heavier textbooks from the higher shelves.

The circle drawn in the diary was part of a ritual casting of the contact other plane spell, and the runes are tied to an entity from the Outer Planes.
With Drusk's religion help, the drawing of the tome with the cover image of a monstrous creature is not one of the well known gods, but the distinctiveness of the tome makes it likely that a librarian or scholar can find out if this is a well-known text or not.

Leaning on Hildi's background feature (researcher), I'm hoping I know exactly where to go to find that information.

Quote from DirtyDogP >>

Leaning on Hildi's background feature (researcher), I'm hoping I know exactly where to go to find that information.

You might think of other places, but you can always visit the Blackstaff Tower. It is a fortress and a wizard training academy all in one, so would have an impressive library. While this wouldn't be important enough to bug Vajra directly, surely a lower-level apprentice could be loaned for an afternoon to help with the library research, since you have done favors for the Blackstaff in the past.

Perhaps, in his grief, Yellowcrest persued some sort of dark ritual, which lead him to the book.  Maybe to bring back his family?  Maybe some sort of ritual to bind spirits to a place or item, ie his family to the house, or more likely an item he could carry about with him (since he sold the house).

Could we investigate if any such rituals exist, who might know about them and maybe Yellowcrest had visited them?

Hildigrim and Drusk head to the Blackstaff's tower!

Before following Hildigrim, Drusk suggests that Jorin continue playing games with the ghost, to verify information.
If he isn't interested in Charades, maybe something like 20 Questions will work better.

(Drusk did a few games as an acolyte in the elf temple, but he was disappointed when he found out that he could win more often than not with 1 question:
"Is it the chief elf god Corellon Larethian?")

What is Quillary up to? (Could stay to help Jorin, visit the manor that the Yellowcrest's used to live in, or return to the graveyard. Or whatever you'd like.)

Hmm, ok, Jorin will attempt to mime what he's thinking to the ghost.  He'll pretend to be Lord Yellowcrest, off on a trip, walking around looking at things as if they are new, then turn around and go through a mime door, then act as if he came upon the remains of his family, with a melodramatic hand to the head and NOOOOOOO type motion.

Then he'll look at the book and look at where the imaginary dead family members are, then back to the ghost for confirmation.

Quillary will sit and watch Jorin for a good twenty minutes as he and Sarah mine the horrors she has seen, then she hunts about in Hildi’s room and procures parchment, ink, and a quill. She writes on the paper, “Sarah, can you read this?” and shows it to them.

omg that is such a better idea

I like to think Quillary thought of it right away, but watched Jorin and Sarah do their thing for so long because she loves the emotional interaction. 🥺

i'd like to say GuiltySparc thought of it too and was just roleplaying Jorin's low intelligence, but that would be a lie

Quote from Guiltysparc >>

Hmm, ok, Jorin will attempt to mime what he's thinking to the ghost.  He'll pretend to be Lord Yellowcrest, off on a trip, walking around looking at things as if they are new, then turn around and go through a mime door, then act as if he came upon the remains of his family, with a melodramatic hand to the head and NOOOOOOO type motion.

Then he'll look at the book and look at where the imaginary dead family members are, then back to the ghost for confirmation.

Sarah shakes her head no.
She stands up stiff with a haughty expression, raises an arm, then mimes stabbing downwards 8 times. (She does pause midway, to count how many stabbing motions she made so far.)

Quote from Mingofaust >>

Quillary will sit and watch Jorin for a good twenty minutes as he and Sarah mine the horrors she has seen, then she hunts about in Hildi’s room and procures parchment, ink, and a quill. She writes on the paper, “Sarah, can you read this?” and shows it to them.

You see that Sarah's lips move as she is looking over the paper, and then nods yes.

(Hildigrim would have shared his observation, that the writing in the diary started with someone who had to practice writing her own name, but over the years was able to write fluently.)