The first chapter of this entry is a look into the Doctor's hearts and mind as he undergoes his regeneration at the end of the eleventh Doctor's time and the start of the twelfth Doctor's reign. Therefore the dialogue will match that seen on screen. This is deliberate.
The inevitable time of renewal always brought with it confusion, fear and pain. For a time, the Doctor would forget who he was, or lose control of himself, and those around him would recoil, gripped by their own fear - after all, the man they might have known for years was suddenly gone, replaced by someone completely different and not in control of their faculties.
For a few instances, all the past lives of the Doctor would rebound into him, like a chord snapping back on itself to the start of its journey, and the Doctor would feel the pain of each and every one of them - every companion lost or left behind, every life he failed to save - it was as though he relived each moment.
It was no wonder he often seemed... unstable, to his companions. As great as a Time Lord's mind was, even he had trouble processing so much in one go.
His eyes were now not only only old in spirit but in appearance, he could somehow feel that, as he looked at the young woman in front of him, that somehow held huge significance to him... the name Clara sprang to mind, and then his surroundings came into sharper focus. The huge spire with the tubes that hummed with tremendous power. The lights and buttons and controls that all seemed to be bright with colour and vibrancy.
All of a sudden, pain shot through him. He staggered slightly, and gasped.
"Kidneys!" He exhaled the word. The woman he thought was called Clara looked at him with bewildered brown eyes.
"I've got new kidneys!" The Doctor exclaimed. A realisation hit him. "I don't like the colour!"
"Of your... kidneys?" Clara (?) sounded as confused as she looked.
The ship - the... the... the name of which escaped him, lurched suddenly, nearly tipping them both onto their behinds.
"What was that?" Clara was worried.
"Now don't panic my dear..." The Doctor propped himself up against the control console, awkwardly aware that the symbols and buttons and dials were blurring into one. "Just, one question... do you know how to fly this thing?"