The Warden and Alistair meet Flemeth in the Korcari Wilds when Morrigan comes across them and presents them to her. Their assignment was to recover treaties that have been signed by the other races promising the Grey Wardens help in their time of need. Flemeth retrieved the documents in question from their hiding place and kept them safe for the Wardens' eventual need for them.

Flemeth later rescued the pair from the Tower of Ishal following the disastrous Battle of Ostagar and healed them. When she sent them on their way to build an army, she had Morrigan go with them, saying that they would need her skills and that Morrigan wanted to see the world anyway. While with the party, Morrigan often speaks of Flemeth's lessons, which frequently focused on the importance of power over all else. Morrigan will also tell the Warden the story of Flemeth's origins as the Chasind know it, and later, Flemeth's own version of her story. Morrigan is quick to point out the possibility that neither version is true.

Eventually, Morrigan will ask the Warden to recover Flemeth's Black Grimoire, which is held by the Circle of Magi. When recovered from the first Enchanter's study at the Senior Mage Quarters in the Circle Tower, the Grimoire can be given to Morrigan for a large bonus to Morrigan's approval. However, what Morrigan learns from the Grimoire disturbs her deeply - whenever Flemeth grows too old, she raises a daughter to follow in her footsteps, only to then possess that daughter and discard her old body. Morrigan realizes that this is what Flemeth intends for her upon her return. To save herself, Morrigan asks the Warden to kill Flemeth. Upon confronting Flemeth, The Warden may choose to kill her. If she is attacked she will transform into a high dragon.

See Flemeth the Shapeshifter for tips on how to defeat her.

Morrigan makes the Warden aware that she cannot go to Flemeth's; if she is present when Flemeth is defeated, she fears that Flemeth will use that opportunity to immediately take over her body. Therefore if you do have Morrigan in your active party when you approach Flemeth's hut, Flemeth will not be present to initiate this encounter.

When confronted, Flemeth offers the Warden a deal: in exchange for her real Grimoire, the Warden will return to Morrigan and tell her that Flemeth is dead. Flemeth claims that she wishes to see what Morrigan will do if left to her own devices, although she does not rule out the possibility of revenge.

After defeating Flemeth or agreeing to lie to Morrigan, the Robes of Possession can be found in a chest in Flemeth's hut along with Flemeth's Real Grimoire. The Robe allows Morrigan to keep her unique look and is suitable for the middle-to-end game.

Flemeth makes a return in Dragon Age II. Early in the game, the Hawke family along with Ser Wesley Vallen and his wife Aveline Vallen were attempting to escape the Blight in Lothering. Flemeth, in dragon form, saves them from Hurlocks.^[2] Materializing as a more attractive human form, Flemeth attributes her actions to mere curiosity towards Hawke for defeating an Ogre earlier. Afterward, Flemeth offers Hawke safe passage with the request that Hawke delivers an amulet to a Dalish Keeper, Marethari from the Dalish Elf Origin, whose clan resides near Kirkwall. This begins the quest Long Way Home. She also warns Hawke and Aveline that Wesley is dying from darkspawn corruption, forcing Hawke or Aveline to put him out of his misery. As these events occur during the fall of Lothering to the darkspawn hordes, it is before the Warden can perform Morrigan's quest to kill Flemeth. ^[3] When Cassandra expressed disbelief about Flemeth's involvement, Varric Tethras suggests he relate the tale of the Warden, to which Cassandra admits that she shouldn't be surprised to hear of the witch's involvement.

Before Hawke or Aveline kills Wesley, Flemeth mentions that the only cure for the taint is to become a Grey Warden. Hawke/Aveline will respond by saying that they all died at Ostagar. Flemeth corrects them, stating "Not all, but the last are now beyond your reach". Once the choice is made, Flemeth will give a cryptic warning about their troubles just beginning.

After giving the amulet to the keeper and performing a Dalish ritual upon it, Flemeth is reborn, as she stored a part of herself within it. She reveals this was a form of security in case Morrigan was successful in convincing the Warden to kill her. If asked "Are you real?" she will comment on the fact that unlike mortals, she is not limited to being in one place at a time. Her current self is merely a piece of herself that she has projected, effectively enabling her to live on regardless of whether the Warden killed her or not. She then tells Hawke that change is about to come to the world, and gives a number of cryptic warnings to Hawke and Merrill. After this, she flies away in her high dragon form and does not reappear in the game.