Mysterious Note (Dark Brotherhood)

Mysterious Note is one of the many letters received from Couriers.

Known Location(s)

 * 1) After killing Grelod the Kind for Aventus Aretino, a courier brings this note to the Dragonborn. It contains simply a Black Handprint with the words "We Know", scribed beneath. This note is from The Dark Brotherhood. The next time you sleep, you will be taken to an Abandon Shack and be made to kill one of 3 captives by Astrid to leave. Once done, she will give you the key and ask you to join her by going to the Dark Brotherhood Sanctuary.
 * 2) Seeking the Horn of Jurgen Windcaller for Arngeir, the Dragonborn finds this note in its place at Ustengrav. Written by Delphine, it asks the Dragonborn to rent the "attic room" at the Sleeping Giant Inn in Riverwood.

Mysterious Note #1
We Know

Mysterious Note #2
Dragonborn--

''I need to speak to you. Urgently.''

Rent the attic room at the Sleeping Giant Inn in Riverwood, and I'll meet you.

--A friend

Appearances
The Elder Scrolls V: Skyrim