Madame Vastra is told by an imprisoned and insane murderer that the Doctor’s greatest secret will be taken to his grave, “and it is discovered.” She uses a special soporific to bring herself, Jenny and Strax to a “conference call” in their dreams; she sends a letter to Clara in 2013 to include her in the conference. “Time travel has always been possible in dreams.” River Song (from after “Forest of the Dead”) also attends, and explains Vastra misunderstood the message; it isn’t his secret that has been discovered, but his grave. The Whispermen kidnap Vastra’s group, while Clara awakens and informs the Doctor of what she learned, making him realize the prophecy the Silence had been trying to avert is unfolding; they go to Trenzalore, where the height of the graves is determined by the warriors’ rank. The Doctor’s resting place is a monolithic TARDIS, which is dying and losing control of its “bigger on the inside” properties. They go inside, where the Great Intelligence (in Walter Simeon’s form) is waiting for them; it demands the Doctor speak his true name to unlock the control room. When the Doctor refuses, River (linked to Clara through the conference call) speaks it to save them. The Doctor explains that instead of a body, the TARDIS houses his personal timeline; the days that have and haven’t come to pass. The Great Intelligence steps into the timeline and scatters itself throughout the Doctor’s life, hoping to rewrite all his victories into defeats to gain revenge. Clara follows after it, becoming two of the multiple echoes of herself that the Doctor met in “Asylum of the Daleks” and “The Snowmen”. The Doctor reveals he could see River the whole time and kisses her goodbye; she says if the original Clara is dead, she should have vanished due to being linked to her, prompting the Doctor enter his own timeline to rescue Clara. He does so, but not before she discovers a previously unseen incarnation of the Doctor, who, according to the Eleventh, “broke the promise” that goes alongside the title ‘Doctor’, even though this incarnation defends his actions as “without choice” and “in the name of peace and sanity”.