To join the Dark Brotherhood in Skyrim, you must first complete the quest that a boy in Windhelm gives you, then trigger a kidnapping event by sleeping in a bed and following the instructions you’re given there.

Step-by-step walkthrough

1. Hear about the “kid in Windhelm”

  • Talk to an innkeeper or guard and ask about rumors ; they’ll mention a boy in Windhelm trying to contact the Dark Brotherhood (this can be Ivarstead/Riverwood/other inns depending on who you ask, but the boy is in Windhelm).
  • This adds a quest pointing you to Windhelm, usually called “Innocence Lost.”

2. Find Aventus Aretino in Windhelm

  • Go to Windhelm , head into the city, and look for the Aretino Residence in the Gray Quarter area.
  • Inside you’ll meet Aventus Aretino , a boy performing the Black Sacrament to summon the Dark Brotherhood.
  • Talk to him and accept his contract to kill Grelod the Kind , the cruel head of the orphanage in Riften.

In lore terms, Aventus is convinced the Dark Brotherhood will free him from the orphanage, which is why this whole questline begins with a child and an assassination.

3. Complete “Innocence Lost”

  • Travel to Riften and locate Honorhall Orphanage.
  • Go inside, find Grelod the Kind , and kill her; you won’t get a bounty if you do it stealthily and leave quickly.
  • Return to Aventus Aretino in Windhelm and tell him the job is done to complete “Innocence Lost.”

4. Wait for the mysterious letter

  • After “Innocence Lost” is done, travel around or wait a bit (a few in‑game hours to a couple of days, plus at least one city change).
  • A courier will eventually find you and deliver a letter with a black handprint and the words “We know.”
  • You don’t have to read the letter for the story to progress, but it’s a cool flavor moment confirming the Brotherhood is watching.

5. Go to sleep (the kidnapping trigger)

  • After receiving (or just having triggered) the letter, sleep in any owned/rented bed for a few hours.
  • Instead of waking up where you slept, you’ll wake up in a remote shack with Astrid , a Dark Brotherhood assassin, waiting for you.
  • She tells you she “stole” your kill from Aventus’s contract and now you owe the Brotherhood a murder.

6. The “Which one will you choose?” moment

  • In the shack are three captives tied up.
  • Astrid wants you to kill one of them to prove you’re worthy.
    • It doesn’t matter which one you kill for joining purposes; killing one is enough.
* Some players kill **all three** ; this slightly impresses Astrid but doesn’t meaningfully change the main outcome.
  • Once you’ve made your choice, talk to Astrid again.

7. Officially joining the Dark Brotherhood

  • After your “trial kill,” Astrid gives you the location of the Dark Brotherhood Sanctuary near Falkreath and a password.
  • Go to the Sanctuary entrance (a black door in a rocky area outside Falkreath) and when asked the question “What is the music of life?” , answer:
    • “Silence, my brother.”
  • The door opens, you enter, talk to Astrid inside, and you’re now formally a member of the Dark Brotherhood.
  • Inside the Sanctuary you can also find one of the Stones of Barenziah on a table near the entrance hall, useful for the “No Stone Unturned” quest.

Extra tips and viewpoints

  • Speedrun approach: If you know where Aventus is, you can go straight to Windhelm, start “Innocence Lost,” kill Grelod, then push time forward and fast‑travel between cities until the courier spawns.
  • Role‑playing angle: Joining the Dark Brotherhood suits stealth/assassin builds, but it can be an interesting moral contrast for paladin‑type characters who later choose to betray the Brotherhood.
  • Loot and rewards: The Dark Brotherhood questline gives unique gear like assassin armor , a powerful horse (Shadowmere), and access to well‑paid assassination contracts.

From a story perspective, the Dark Brotherhood line is one of Skyrim’s darkest, dealing heavily with killing, betrayal, and moral gray areas; it’s popular in forum discussions even today for how memorable the twists and characters are.

TL;DR:

  • Talk to an innkeeper/guard → learn about the boy in Windhelm.
  • Go to Windhelm , meet Aventus Aretino , start “Innocence Lost.”
  • Kill Grelod the Kind in Riften, report back to Aventus.
  • Wait for a courier and the “We know” letter, then sleep in any bed.
  • In the shack, kill one captive for Astrid , then go to the Sanctuary near Falkreath and say “Silence, my brother” at the door to join.

Information gathered from public forums or data available on the internet and portrayed here.