I appreciate the fungal dead man’s hand 
. And I should get another year up for Pando soon.
It would seem we can reasonably rule out Burgraff Telsberg‘s scribe as a spy for Agnes, if we were to further investigate that. Likewise, it seems unlikely to be the Burgraff’s steward or messenger as well (I can’t recall if we got the letter by redcap).
Likewise, Agnes was quite vague about who found the vis. It could just be a peasant with magic lore otherwise unaffiliated with Agnes. On the other hand, if it’s a hedge wizard in Agnes’ court or a hermetic magus giving vis to mundanes, then things get a bit more interesting