Riordan has told the Warden that when an archdemon is slain, its essence will pass on to possess the nearest darkspawn, making the archdemon essentially immortal. To put an end to the Blight, a Grey Warden must strike the fatal blow, causing the essence to be drawn into himself and killing both. Having learned this disturbing new information, the Warden retires to his or her room to rest before the coming battle.
- Leave Riordan's room and cross the corridor to your room. Morrigan will be waiting for you (she will appear at this point even if she has previously left the party).
- She claims to know a ritual that will allow the Warden who kills the archdemon to avoid his/her fate. She explains that it is a form of blood magic known long before the Circle of Magi was ever created. This dark ritual will ensure that the essence of the archdemon is lured into an unborn child bearing the taint rather than the Grey Warden slaying the archdemon. Morrigan believes that the child will survive and possess the soul of an Old God, freed of its darkspawn corruption. This ritual, Morrigan claims, is the reason Flemeth rescued the Wardens and the reason Morrigan had to accompany them. Flemeth's reasons for this are unknown.
- If you are male, then you can perform the ritual with Morrigan; it is not necessary to have been in a romantic relationship with her.
- If you are female, or are male and turn Morrigan down, she will suggest that she perform the ritual with Alistair or Secret Companion. If you agree to raise the topic with one of the other Wardens, then go to the Guest Room and discuss it with them. Once your discussion is concluded, you will return to Morrigan to report the outcome. You have one final chance to turn her down at this stage.
- If the ritual is refused, Morrigan will leave the party immediately. If the ritual proceeds, she will stay for the final battle.
- If the Warden is in a romance with Alistair, Leliana or Zevran, then Morrigan will mention them and suggest that their feelings are a reason to undergo the ritual and stay alive. If the Warden is in a romance with Morrigan, she will say that her feelings make her all the more determined to get you to do the ritual.
- The Battle of Denerim will start.
- 7500 XP (either option)
- The choice made during this quest will affect the outcome and Epilogue. If Morrigan's offer is accepted, then, regardless of whom the ritual was performed with, the Warden will automatically strike the killing blow against the Archdemon and will survive. Otherwise they will die unless choosing another Grey Warden to perform the final blow, in which case that Warden (Secret Companion or Alistair) will die.
- It will also affect which Ending Achievements can be earned in the playthrough. It is necessary to accept Morrigan's offer to earn "A Dark Promise" and to turn her down to receive the other three achievements (and hence also the "Perfectionist" Completionist Achievement for exploring all four endings).
Note: Console versions of the game only have two ending achievements rather than four: one for accepting Morrigan's ritual and one for rejecting it. However, it is still necessary to explore all four endings to obtain the console Perfectionist achievement. If you choose to accept Morrigan's ritual and the Warden takes the killing blow you will receive "A Dark Promise Achievement".
- If the Ritual is accepted, Morrigan will have her child with her in her journeys with the Inquisition after the quest Wicked Eyes and Wicked Hearts. His presence or absence greatly affects Morrigan's interactions with Flemeth and has possible far-reaching consequences extending into future unwritten story.
- If Alistair is a Warden at the time of Dragon Age: Inquisition (and was not in a romance with the Warden?), the player can speak with him during the quest Here Lies the Abyss, inquiring about the location of the Hero of Ferelden. He will remark that the Warden did things the night before the battle, and that he or she "walks a dark path."
- Depending on the choices made by the player, Morrigan may reference the ritual during the DLC quest Witch Hunt (and, indeed, the Warden's motivations in that game may be influenced by whether he chose to undertake the ritual and conceive a child with Morrigan). However, due to a bug, Morrigan may "forget" that the Warden undertook the ritual depending on which version of the Warden is imported from Origins or if another DLC game is played and that version imported. The bug has been patched on some versions of Witch Hunt, but is still present in the PS3 Ultimate Edition.