Doctor originally planned to use a Time Lord weapon known as the Moment to destroy the Time Lords and Daleks. However, after being shown the Tenth and Eleventh Doctors during "The Day of the Doctor", he works together with them to change the assumed outcome of the Time War: thirteen incarnations of the Doctor team up together to freeze Gallifrey in time and place it outside of their universe (protecting it and the remaining Time Lords), while the Daleks destroy themselves in their own crossfire once Gallifrey is gone. The War Doctor does not retain the memory of these events and the Doctor spends centuries believing he burnt Gallifrey until the Eleventh Doctor's time; this is because the time streams are out of sync after the War Doctor meets his future selves and the altered events are only known to the Doctor once they occur in the Eleventh Doctor's experience and become part of his memory. Indeed, earlier on in the episode, both the Tenth and the Eleventh Doctors mistakenly believe that the War Doctor killed all of the Time Lords on the last day of the Time War. After being informed that the plan to save Gallifrey was successful, the Eleventh Doctor sets out to find Gallifrey and restore the Time Lords. In "The Time of the Doctor", the Doctor visits the planet Trenzalore where he discovers a question being broadcast through all of time and space through a crack in the universe: "Doctor Who?" The Doctor realizes that the Time Lords are attempting to return to the universe and will come back if he speaks his true name. Due to "half the universe" surrounding Trenzalore, a siege begins that lasts centuries as the Doctor knows that if the Time Lords return, the Time War will begin anew. With the Doctor on the verge of death, Clara Oswald pleads with the Time Lords through the crack to intervene and save the Doctor. Through the crack, the Time Lords grant the Doctor a new regeneration cycle, saving his life before sealing the crack again. In "Hell Bent" (2015), it is revealed that Gallifrey returned to the universe around the time of its end. After escaping his confession dial in "Heaven Sent" (2015), still furious over the death of Clara Oswald in "Face the Raven" (2015), the Doctor manages to depose Rassilon—who had put the Doctor there to begin with for