• Clara advising the First Doctor to steal his Type 40 TARDIS on Gallifrey (colourised from "The Aztecs").
• Clara seeing the Second Doctor running across a palm-tree lined beach in a fur coat (with footage taken from "The Five Doctors").
• Clara calling out for the Third Doctor as he's driving away in Bessie ("The Five Doctors").
• Clara chasing after the Fourth Doctor on Gallifrey ("The Invasion of Time").
• Clara finding the Fifth Doctor trapped ("Arc of Infinity").
• Clara trying to find the Sixth Doctor in his TARDIS.
• Clara attempting to rescue the Seventh Doctor from falling off of a cliff ("Dragonfire").
• Clara running after the Eighth Doctor.
• Clara watching the Tenth Doctor as he stands in The Library.
• The Ninth Doctor runs past Clara while she was inside The Doctor's time stream.

• The First Doctor asking Ian and Barbara ‘Have you ever thought what it's like to be wanderers in the fourth dimension?’ ("An Unearthly Child").
• The Sixth Doctor saying to the Time Lords ‘Daleks, Sontarans, Cybermen! They're still in the nursery compared to us’, ("The Trial of a Time Lord").
• The Second Doctor saying ‘There are some corners of the universe that have bred the most terrible things’ ("The Moonbase").
• The Fourth Doctor saying ‘Do I have the right?’ to Sarah Jane Smith ("Genesis of the Daleks").
• The Ninth Doctor saying ‘Absolutely fantastic’ ("Bad Wolf/The Parting of the Ways").
• The Tenth Doctor presenting himself in "Voyage of the Damned".
• The Fifth Doctor saying ‘So you see’ to Stotz ("The Caves of Androzani").
• The Eleventh Doctor saying ‘Hello Stonehenge!’ ("The Pandorica Opens/The Big Bang").
• The Third Doctor saying ‘It was the daisiest, daisy I'd ever seen’ to Jo Grant ("The Time Monster").

Conference Invite

Madame Vastra and Jenny Flint learn of a prophecy, told by a condemned and insane man, regarding The Doctor - in particular, he claims to have a ‘secret’ about The Doctor. Using soporific drugs they hold a conference call to bring themselves, Strax, River Song, and Clara Oswald across time and space into a dream realm where they explain the prophecy relating to the planet Trenzalore. However, during the conference call, Jenny is attacked by strange faceless creatures known as The Whisper Men,. Thinking quickly, River Song forces Strax, Vastra and Clara to wake up before they too are attacked.

Clara wakes up back in contemporary London to find The Doctor looking for her. She quickly explains to him what she remembered, including the attack on his friends and the apparent death of Jenny. The Doctor decides that they must go to Trenzalore to save them even though, as he explains to Clara about the prophecy relating to his death, that Trenzalore will be the place he will be buried, and so is the one place that he should not travel to.

The TARDIS however, resists, unwilling to cross The Doctor's timeline, but he manages to crash the time-machine on to the planet which they discover has been ravaged by a giant war in the past and is now covered in gravestones. One of the stones looks like a massive effigy of the TARDIS, but The Doctor reveals that it actually is the future TARDIS, dying and thus unable to control its transdimensional functions. The Whisper Men then appear and attack the duo. Clara however, notices that one of the gravestones is for River Song, something that The Doctor realises is impossible due to her physical death at the Great Library (see "Silence in the Library/Forest of the Dead"). River Song then appears to Clara, and tells her that although she can see her due to the conference link, The Doctor cannot. With River Song's help, Clara suggests that the gravestone is actually a secret entrance to The Doctor's tomb. Realising that this is the case, and so as to escape from The Whisper Men, The Doctor and Clara crash through the stone and so enter The Doctor's TARDIS.

River Song

Elsewhere, Vastra and Strax, having been attacked by The whisper Men when they woke up from the conference call, find themselves outside the giant TARDIS, along with Jenny's comatose body; Strax manages to revive Jenny before they are surrounded by more Whisper Men. They discover that The Whisper Men are part of The Great Intelligence led by Dr Simeon (see "The Snowmen") and although he has died, he remains as a conduit for The Whisper Men, who can shift their appearance to look like him.

While Clara and The Doctor are running through the telepathic fields of the dying TARDIS, Clara begins to remember the events of when she was trapped inside the TARDIS (see "Journey to the Centre of the TARDIS") through the telepathic link with the TARDIS. The Doctor and Clara soon arrive outside the giant TARDIS, where they are held, along with Vastra, Jenny and Strax, by Dr Simeon and The Whisper Men.

The Whisper Men

Dr Simeon stands at the door to The Doctor's tomb, stating that only The Doctor's name will open it, demanding they gain access or else he would have The Whisper Men stop his friends' hearts. The Doctor refuses but River Song appears at the last moment. Forced to act, so as to save everyone, she speaks The Doctor's real name allowing the doors to open. Inside they discover the Console Room but instead of where the console would normally be there is a pulsating column of light. The Doctor tells them that it is the scars of time travel that he has left on the universe.

Dr Simeon declares his intention to climb inside and undo the deeds of The Doctor's past; though Dr Simeon knows he will die, the act would also destroy The Doctor. His entrance into the column results in The Doctor collapsing to the floor, as he is ‘dying all at once’. As The Great Intelligence disappears, Vastra, Jenny and Strax find that all the stars outside are going out, erased from existence by the new timeline. Jenny also disappears, and Strax denounces Vastra as ‘reptile scum’ - the new timeline making him forget that they are friends. Vastra is therefore forced to kill Strax to save herself.

Clara's knowledge about her existence deepens, and she realises that if she also enters the timeline, she will be able to save The Doctor from Dr Simeon's meddling. River Song however, tells her that she will not be able to come back, and a dying Doctor tells her not to go, but she decides to enter the timeline anyway. As she is engulfed by the pulsating column of light she calls to The Doctor, ‘Run, you clever boy. And remember me’, before she disappears.

TARDIS End

Clara witnesses events from all the previous incarnations of The Doctor and helping him along (including helping the First Doctor and his granddaughter Susan Foreman escape from Gallifrey in the correct TARDIS and the events that occurred in "Asylum of the Daleks" and "The Snowmen"). Having saved The Doctor's timeline (subsequently restoring Jenny and Strax along with the rest of the universe), she finds herself falling indefinitely and considers her role as the impossible girl done.

The Doctor, restored to normal by Clara's act, decides to rescue her by entering the column of light. River Song, who believes he still cannot hear her, yells at him to not be so stupid and tries to slap him; however, he is able to catch her wrist. Realising that The Doctor has also been able to see her she sadly asks why he has been ignoring her, and he tells her that goodbyes are too painful, so she must exist as an echo. River Song makes The Doctor either give her a proper goodbye or promise to see her again; The Doctor commits to the latter. The Doctor then enters his own timeline in an attempt to save Clara.

He discovers that Clara has fallen into a cavernous place, and sees ghosts of his past incarnations race past her. The Doctor's voice guides Clara to catch the leaf that was responsible for her life (see "The Rings of Akhaten") and this helps The Doctor find her. They embrace but as they are about to leave, they spot one more figure nearby, whom Clara has never seen before. The Doctor reveals that this is one of his incarnations that didn't hold the moniker of The Doctor due to his actions in life.

The Doctor explains to Clara that his real name was not the point; he chose the name The Doctor himself like a promise, and this mysterious man was ‘the one who broke the promise and this is his secret. As Clara collapses from exhaustion, the figure defends himself, saying that he had no choice and that his actions were ‘in the name of peace and sanity’. The Doctor acknowledges this to be true, but that it had not been ‘in the name of The Doctor’. As The Doctor leaves, carrying the unconscious Clara, the man turns to look at them, showing his elderly face, as the screen credits identify him as ‘The Doctor.