Blood-stained Note is somewhat alarming.

A plain, unadorned note.
Properties
Notes
Author: unknown
Rarity: Common
Weight: .05 kg / 0.1 lb
Price: 14 gp
Where to find
- In a mailbox in Lower City X: 123 Y: -2
Text
[A strip of paper, with the following words written in blood.]
I found you.