They will tell you that if you kill one of the other three people in the room, they will release you. Choose a person, and kill them. Speak to The Dark Brotherhood again, and they will tell you to meet them at their lair in the pine forest in the far southwest corner of Skyrim. ...
Sacred Witness, Volume 2: In Babette’s room in The Dark Brotherhood Sanctuary. The Red Kitchen Reader, Volume 1: In the Frostmere Crypt. The Red Kitchen Reader, Volume 2: In New Gnisis Cornerclub in Windhelm. Three Thieves, Volume 1: In the...