King Tut
Alchemy check on the oily residue...booyakasha BR 10 = success.
So we have a big shattered mirror, a small whole mirror, an oily vial, and a big wooden mallet, all inside a small cottage floating in a void with a (previously) bricked up cellar below.
I use the small mirror to make an "endless mirror" with the bigger, reconstructed one. I'll also move the larger mirror aside and see if there's anything else there.
Anyone have any clue what is going on?