Letter E2-03

Members of the Ushiromiya Family and its household, have you now reached the climax of the riddle of the gold's epitaph?
There is only one way you all can stop me: by solving the epitaph's riddle.
There are no other options left to you that will result in the suspension of my ceremony.
I humbly ask that you take care not to misunderstand your current situation.
Searching for me will prove useless.
Attempting to escape will prove useless.
Trying to deny me will prove useless.

-- Beatrice the Golden

P.S.
I borrowed those two corpses for my ceremony.
They will be returned to you in due time, so I crave your indulgence.
Also, these keys belong to you, so I return them to you now.