The Elder Scrolls V: Skyrim is a larger-than-life game with hundreds of quests and a healthy array of factions to choose from. The most mysterious among these is the Dark Brotherhood. Seen before in The Elder Scrolls IV: Oblivion, this motley crew of assassins makes for a spooky, and sometimes charming, addition to any playthrough. Joining the elusive assassin's guild takes time, though, and a lot of dedication.
Source：https://www.cbr.com/skyrim-how-to-join-the-dark-brotherhood-full-guide/
