They persuade the Doctor to take action to end the Time War, offering him a selection of potions to control his regeneration.
He reluctantly accepts that with all of reality threatened and the universe "on the brink", there is not much need for a doctor, and chooses a potion designed to initiate his regeneration into a hitherto unknown incarnation of the Doctor as a "warrior" (described in credits as the "War Doctor" and played by John Hurt).
The countdown is stopped and all present negotiate a perfectly fair peace treaty, as they no longer know which way to skew it.
The War Doctor, now convinced that detonating the Moment will save many more lives in the longer term, is returned to his time by the Moment.
The Moment offers to show the Doctor what this will turn him into and opens a fissure linking him to the Tenth and Eleventh Doctors.