Anastacia of Astora

 is a Fire Keeper in Dark Souls. She keeps the bonfire in Firelink Shrine lit. She is voiced by Emma Pierson.

Location
She can be found just underneathe the bonfire, down the stairs located just to the left of the Crestfallen Warrior.

Plot
Initially she is unable to speak, for her tongue has been removed sometime long ago. Despite this, players can still interact with her: as with other Fire Keepers, Anastascia has the ability to upgrade Estus Flask levels in exchange for Fire Keeper Souls.

Death and Revival
At some point while the player is down in Blighttown (after retrieving the Fire Keeper Soul from Blighttown or after the second Bell of Awakening has been rung), Knight Lautrec of Carim will kill Anastacia, deactivating the bonfire in Firelink Shrine. Anastascia leaves behind the Dingy Set and the Black Eye Orb. The Black Eye Orb is an invasion item, allowing players to find and invade Lautrec's world to defeat him.

Upon reaching Anor Londo, the Black Eye Orb may be used in the hallway just before the Ornstein and Smough fight. Killing Lautrec after invading his world with the Black Eye Orb yields (among other things) Anastascia's Fire Keeper Soul.

Returning Anastascia's soul to her cage will revive her, reigniting (and fully kindling) the Firelink Shrine bonfire. Her tongue will also be restored, allowing the player to engage in conversation with her.

Drops
Her drops can only be obtained if Lautrec of Carim kills her.
 * Dingy Set
 * Black Eye Orb

Dialogue
Upon being revived: "...Th, thank you...I am Anastacia of Astora...Now I can continue my duty as a Keeper...But...I only hope that my impure tongue does not offend.

Talk option: "...Forgive me...I am impure, my tongue never intended for restoration...Please, if you have any heart...Leave me be..."

After giving Frampt Lordvessel and offering at least one Lord Soul: "... Frampt has told me of you... That you have agreed to link the Fire... I thank you, sincerely... Finally the curse of the Undead will be lifted, and I can die human... I am powerless, but I will do what I can... Please, save us all... Please."

Backstory
Anastacia is mentioned by several characters (including herself) to be "impure", especially of speech. However, what exactly made her so controversial is never discovered, as she tells very little to the player even with her tongue restored. It has been hinted from item descriptions that Anastacia chose her own banishment and even imprisonment.

Trivia
Anastacia's voice actor, Emma Pierson, also voices Dusk of Oolacile.