Once upon a time, the Impossible Girl, Clara Oswald, loved the Doctor, and he loved her in return. Clara Oswald saved the Doctor, and he thought he saved her in return. The Doctor was wrong. He watched in horror as Clara’s psyche shattered, the countless memories of her echo lives bleeding through: “I’m the Impossible Girl; I was born to save the Doctor.” The Doctor blocked the torrent of time overwhelming his dear friend, just as he’d done for her predecessors Rose and Donna after they walked too long in eternity.
However, as he regenerated on Trenzalore, Eleven becoming Twelve knew his job saving the Impossible Girl wasn’t complete. He had to save Clara; he had to save the latest member of his family. To that end, the regenerating Time Lord willed himself to become a family man. Twelve took on his Mother-In-Law’s distinctive Scottish accent, so Clara couldn’t ignore him. As for his face, that had been worn by two human fathers. Ten saved the first, Caecilius, and his family from the fires of Pompeii. The Doctor didn’t save the second, John Frobisher, but he watched the dark tragedy as the civil servant killed his own family and himself to save them.
To his shame, Twelve had to be Frobisher as well as Caecilius in order to goad Clara, in order to irritate her like an oyster irritates a grain of sand into becoming a round pearl. Clara, you see, was no longer a round pearl. She was baroque, misshapen. Blocking her memories helped, but the fundamental damage remained. He had to reestablish her full personality matrix, and that would be a challenging process that would mark them both forever.
Unfortunately, Twelve couldn’t pretend to be; he could only become. The blunter emotional tools he needed to reshape Clara were intrinsically him, now, and he’d have to learn to weld them himself, just as he used them on her. Twelve noted his progress with Clara and with himself in his new favorite medium — chalk. First, Twelve noted that the necessary memory block had an unforeseen downside. Because Clara could no longer remember encountering his previous selves in his time stream, she no longer possessed the broader perspective necessary to accept his latest incarnation. Fortunately, Eleven foresaw that snag, placing an encouraging final phone call. Second, Twelve noted that because Clara could no longer remember being a good Dalek, he couldn’t use her own experience directly to test her morality. He had to actively embrace the prejudice that both strengthened and sickened him in order to provide Clara with the context she required.
They travelled on. He cried out as Robin Hood dragged Clara through the window. He thanked the gods he knew didn’t exist that she had no memories of those previous fractured falls and fractured deaths. Twelve cursed the gods he knew didn’t exist when his slaved Tardis used Clara’s non-Gallifreyan time line to reach his home. He pretended not to realize what happened, and shed an inner tear for the Echo Clara of Gallifrey that still called out to his Impossible Girl. He shed three more inner tears, recalling Clara’s three-way mirror, realizing that subconsciously she was still shattering.
They travelled on. Twelve noted the irony in chalk as he had to use the same memory worms that Strax almost employed upon Victorian Echo Clara, not once, but twice. First, he used them to erase her memories of his time stream. Then, he used them to erase Clara’s memory for the time heist. He hoped that repeated exposure to the worms wouldn’t cause Clara any lasting damage. Twelve also hoped that Karabraxos woman wouldn’t trigger Clara’s memories of living countless lives and burning in time as the Impossible Girl with the burning of her clones.
They travelled on. Twelve noted wistfully in chalk that they reached a crisis point with the Skovox Blitzer at Coal Hill. Clara frenetically endeavored to balance two lives. Twelve realized that she was subconsciously compensating for all the echo lives crowding at the edges of her awareness. He needed to relieve some of the pressure Clara no longer had words for even if she left him, so he made the most of the Moon’s moral conundrum. As she ranted at him later, Twelve contented himself with the fact that she ranted with a full array of layered emotions. It wasn’t just the mantra: “I’m the Impossible Girl; I was born to save the Doctor.
Clara didn’t leave him, however. She consciously used the word “addiction” to mask the deeper damage. She even took on his darker personality traits, his distance from humanity, in order to distance herself from the echo humanities crowding at the edges of her awareness. As Twelve banged his head against the chalk board in frustration. He remembered the apt lines from William Blake:
Tyger Tyger, burning bright,
In the forests of the night;
What immortal hand or eye,
Could frame thy fearful symmetry?
“Clara, my Clara,” he sighed. “What immortal hand or eye could reframe your fearful symmetries into one?”