Based on a gifset I saw on Tumblr.
…
What do Time Lords fear most?
The Doctor turned slowly, his hearts pumping furiously in foreboding, and there it was, behind him- his door, the number 'eleven' glaring at him from the shiny black plaque. It seemed to loom, drawing his eyes with a magnetic pull, and dragging his body along with it. He stepped closer, willing himself to walk away, to leave this one mystery unsolved and unknown, but he couldn't. The pull was too strong, whether it was his own curiosity or the work of the hotel, or even a combination, he would never know.
If he was right (and he was quite a lot) behind the door was the thing the Doctor was most afraid of in the entire universe. He mind swept through thoughts of Daleks and Cybermen and Weeping Angels climbing into people's minds. He thought of River Song, her mind burning, of Adric, Astrid Peth and poor Rory, dying on the floor of a cave. He thought of Gallifrey itself burning in the Time War, his family and friends, ashes drifting through space. He thought of the Master. Then there was something, deep down, buried in his mind, that told him it was none of these things, but something even more terrifying.
With a steady hand, he reached out and turned the knob, cracking the door wide enough for him to poke his face through. The cloister bell echoed loudly in his ears.
The room was like the others- painfully and over enthusiastically decorated in patterns of red with a bed and bathroom and a bedside table. Except this room was occupied, a solitary figure standing, framed in the resonating glow of red light that was spilling through the open TARDIS doors. His ship looked battered, the paint peeling, scorched, and scratched, as though she'd come out of the business end of a battle. His hearts ached to see her in such as state.
Then, the figure turned around to look at him, and the Doctor saw his face.
"Of course," he whispered, fear, dread and terror flooding him, but it was quickly replaced with resignation, "Who else?" he sighed, with a slight laugh at his own stupidity. It should have been blatantly obvious. The figure in the room pierced him with a deep, sorrowful gaze, his face dirty and lined, before turning his back and once again facing the broken hull of his beautiful ship, as though contemplating it.
The Doctor closed the door on him- his greatest fear- with a loud click. Forlornly, he pulled a 'Do Not Disturb' sign from the depths of his pocket and hooked in on the knob, before turning and walking away without so much as a backwards glance.
…
"I said he was me, I never said he was the Doctor."
"He is my greatest secret."
"What I did, I did in the name of peace and sanity."
"But not in the name of the Doctor."
