Why indeed? Here's a synopsis of events that led to this wacky course of action.
We investigate Cymnea's watch, finding a Necromancer in residence; Tally slaps her wrist and tells her to knock it off and by the way can we search her house for clues pretty please?
We search said house, and find a hidden cellar, seemingly unused, but with traces of faint and ancient magic, barely detectable.
Quinlan's magicks reveal the floorplan of the place, but with a twist-- underlying the entire thing is a glyph of sorts, a complicated circle of sigils. We copy it carefully and distribute it.
Talia Chantris has pored over it and managed to translate it-- and... it is not a magical spell at all, but rather a story, a fragment of myth in an ancient calligraphy. It says, roughly, "Cymnea raised a massive tower of whirlwind from which to watch for the approach of her Doom. But her Doom stepped into the whirlwind and was drawn up behind her, and she saw it not."
Then we, poor wretches at a loss for what to do next, decided that one weird story is worth two, so we go where ALL confused wretches go-- TIR! In hopes of receiving a symbolic vision about Cymnea's Watch, we get Liam to guide us through the jumbled dream-city.
What we saw there was a vision that seemed to be of an actual event, happening in the centuries-past. Five men wearing the ancient livery of Prince Benedict met of a night outside Cymnea's Watch as it stood in those days, seemingly all consulting a paper. They went in, down nonexistent stairs, far below the basement we found, to an altogether different basement, and began to search it. But before they had scarcely started whatever it was they were there to do, they were attacked by shadowy figures and slaughtered, to a man! (One of the assassins held a stone knife with a glyph upon it.) One of the knights, however, Raphaela recognized by badge as a Sorgo ancestor-- and she saw that it was he who held the paper they were all consulting before they entered... Moreover, she noticed that he had gripped it tightly in his fist even unto death, and the assailants did not see it. This is significant because IF he were a fully-empowered Sorgo, and IF this vision were true and not just another lie of the Dreaming, then there is a chance his body might have mummified rather than decayed, and in any event if there are remains to be found, Raphaela wants them found and properly interred in the Sorgo Crypts.
This, then, finds us determined to DIG!!! Not only to find out if there IS some kind of bizarre magic that has somehow altered the very foundation of this building such that that basement never existed to be detected by Quinlan's floorplan magics, but also to find if there are indeed physical remains of those Knights, who DID in fact disappear many centuries ago.