WARNING! THIS PAGE CONTAINS SPOILERS
Astrid is a Nord assassin who leads the Skyrim Dark Brotherhood faction, and wife to the Assassin Arnbjorn, a former member of the Companions and a werewolf. The sanctuary she leads is the last remaining in all of Tamriel. She will give the Dragonborn most of the quests available as a part of the Dark Brotherhood questline.
Unlike the previous tradition of following the Listener, the brotherhood look to her as their leader, in the absence of a Listener, since the death of the previous Listener in the sacking of Bravil by the Aldmeri dominion. The Night Mother remains silent, cared for by the Keeper known as Cicero. She becomes suspicious of his arrival and the unveiling of the true listener, as she is very attached to her position as leader.
Cicero's arrival causes a split to form in the Brotherhood, with some wishing to return to the family's ancient traditions, and others desiring to continue along Astrid's materialistic approach, not truly believing in Sithis. The conflict reaches a fever pitch when the Night Mother finally speaks, naming the player character Listener. Astrid then speaks with the agents from the Penitus Occulatus to exchange the life of the listener for the lives of the Brotherhood. However, the group choose to take both the player's life and the life of every sanctuary member, razing the sanctuary to the ground in the process. However, the player survives the betrayal, along with Babette and Nazir. Astrid also survives, but she is burnt to the point that she is barely recognisable, and her final act is to perform the Black Sacrament to get the player character to kill her, in atonement for her betrayal of the family.