Take some bone from another part of the mammoth skeleton, grind a little bit of dust off it, clean it up using the same method as last time and compare the rags again.
Grab a similar rag, a dustpan and a broom, sweep some dust into it from the Rafters, and wipe it off onto the rag. Is it very similar?
Also, given we're here- check the Maintenance hub for any signs of mammoth skulls.
Can we tell what, if anything, was put in the kitchen garbage disposal last night, aside from the substance Mona was disposing of?
Edit if I can get it in fast enough: Do any of the pieces of exhibits in the rafters show signs they might have been used as a makeshift broom, like the tail of a...
Check the Haunted Catacombs and Basin for any evidence of a mammoth skull.
Also, can we check any rooms other than the rafters that would have tarpaulins to see if they have been disturbed?
Is the candle mentioned in Luke Atmey's testimony present in the kitchen? If so, does it appear to have been used? And is there a way to tell if it resembles candles found elsewhere in the facility?
Additionally, are there any signs at the entrance to the Dining Room of something that may have...
Can we use a darklight torch to see if the remaining parts of the mammoth skeleton react?
Also, a lot of a longshot, is there any chance Mona might know what happened to her helmet?
Are there any more of the crocodile-like marks in the surrounding rooms of the rafters? If so, do they seem to make a trail that could be followed any distance?
Check if any of the other skeletons in the rafters are conspicuously missing bones, particularly any that have three claws.
If that brings up nothing, compare some three clawed animal bones to the marks.
In the Rafters, are there any skeletons/taxidermied animals under disturbed tarpaulins missing skulls, and if so, what kind of animal does the skeleton seem to belong to?
Well, this is a bit disappointing... what a sloppy job for a murder to start us off! No flair, no panache, barely even any cunning! What a shame. And I suppose you all wish to hear of my exploits for the night? Very well. I started off from my lodgings, departing alongside Thanos Automobile and...
I see our host has still failed to put in an appearance. That is not the sort of welcome I- or the rest of you, I suppose- deserve. Not to mention the complete lack of a gentleman's club, or even a basic pub! Tell me, is there at least anything good to drink in the Cellar?