"Why do you keep forgetting things?" Clara asked, breathing heavily, doing her best to keep walking, the Doctor's weight almost fully on her shoulders.
"Side-effects of regeneration" he answered, supporting himself with one hand on the wall, "I-I need some sleep… my nerve cells need time to re-organize." He gasped, and a breathing of golden energy came from his mouth. "Aaah. Ho-how do you humans manage with only one heart? Ah, no. Wait. Next door on the right."
"Are you sure? It is at least the tenth door we-"
"It's the seventh, Clara, and yes, I'm sure." Not true. He still didn't remember where the infirmary was, and he was going random, but he would never admit it. Maybe, he was proud this time around.
Clara opened the door to find an unpretentious room, with a small single bed covered with dusty sheets and an old desk. On a battered bedside table there were a jug of water and a glass. Basically, a long-forgotten guest room.
"Doctor…" she began. It was becoming impossibly hard to bear his weight, and her shoulders were aching.
He sighed. "It's okay, Clara. I just need a bed."
With only one heart beating, his blood couldn't quite reach properly every part of his body. He felt tired and weak and he could not believe that he had been in perfect shape just a few minutes before. The side-effects of his regeneration had caught him off-guard, like a delayed-action bomb.
Clara helped him to sit on the bed and the Doctor barely left her the time to put off his jacket before letting himself fall on the mattress.
"Doctor-" she began again.
"Shush. I don't have much time. I didn't realize at first, but it was a hard regeneration for me, Clara. New regeneration cycle. It wasn't supposed to happen… but it's okay" he added quickly, noticing concern on her face "I'll be fine. But I need to sleep. And…Clara, the TARDIS needs time to fix her face too. We shouldn't stay inside while she does that… and considered her antipathy for you… you wouldn't be safe, so don't wander off. She will be deleting and archiving rooms. Stand… stand by me."
Clara nodded slightly. She didn't want to have to deal with a quite hysterical, post-regeneration TARDIS. Plus, she wouldn't leave the Doctor alone anyway, not now that he felt…well, she didn't know how he felt, after regeneration and everything, but she had the feeling he needed her.
"I'll be right here, okay? You can rest, don't worry."
"Good," he said, closing his eyes and resting his hands on his chest.
It wasn't entirely true that she wasn't safe, because despite the TARDIS being quite temperamental, the ship would never let someone her thief loved risk her life. It was simply that the Doctor wanted Clara near him, because he needed her, even if this new face would never admit it.
He had always lied, and a lot, but he hadn't been so selfish in a while, he thought. Though, if the result was Clara listening to him and standing by him like this, well, he just couldn't complain for this new version of himself. With this last thought, his lips curved in a little half-smirk, and he fell fast asleep.
Clara noticed his lips curve ever-so-slightly, and she wondered what he was thinking. Shortly after, his breath became regular and his whole body relaxed. As his right hand slipped down from his chest to the mattress, Clara instinctively knelt near the bed and took his hand in hers, squeezing it gently. Without realizing it, she placed her head on his chest and closed her eyes. Only when she heard his now both steadily-beating hearts she noticed her actions. She had been moving automatically. Maybe, deep inside, she knew that he was still the Doctor, after all. His double heartbeat helped her accept it, and she smiled, relaxing as he had done, and she leaned against the bed, adjusting herself in a more comfortable position.
Clara had been through a lot of things that mad Christmas. Emotionally, she had never been so tired. The mattress was soft, the Doctor's hand was warm against hers, and the regular rhythm of his hearts was lovingly lulling her: a minute after, she fell asleep without even noticing.
~oOo~
Clara awoke with a start, and somehow she knew that the walls had quaked and that she had heard a loud noise in her sleep. The girl was still leaning against the bed, head on the Doctor's chest. He was still asleep, but he moved slightly and inhaled sharply, and Clara felt his heartbeats become somewhat erratic and faster.
It happened again: the whole TARDIS trembled and Clara noticed the previously gentle humming of the ship had turned into a dull noise. Eyes wide open, the girl glanced anxiously at the Time Lord, who was simply stirring in his sleep, and still wasn't awake. The walls quaked again and she rapidly made a decision.
"Doctor," she called, gently shaking his shoulder, "Doctor, you need to wake up. Doctor!"
The walls quailed once more.
"Doctor! I'm… I'm getting really scared, okay? Doctor!" she half-shouted.
The man suddenly opened his eyes and sat up.
"What?" he exclaimed. "What is it?"
The TARDIS shook again and her noise grew louder.
"Oh, no no no. This is bad."
"Doctor?"
"Shush, again, Clara, I don't have tim- aaah" -he winced- "My head. Listen, you woke me up too soon. It seems that the Old Girl won't be able to stay in the Vortex for some time. She wants to spare energy for her changes. We're still in the Vortex for now but we're slipping out. We'll land very soon. And, Clara, when we land… a lot of… things can smell regeneration energy. A lot of devices can detect it, they were very popular in the Time War, you know, they used them to find you and kill you while you were still regenerat-"
"Doctor," Clara said, interrupting him, "you're rambling. You said you didn't have time."
"Oh, yes, thanks dear. We can't trust the Old Girl now: whatever comes, I think it could enter. And, Clara," he locked his eyes with hers, and the human saw concern and anxiety in his blue irises, "whatever comes, it comes for me and me only. You'll have to be brave, Clara."
"No," she whispered, already suspecting what he wanted her to do.
"Yes. Brave, brave Clara. You're not safe here with me." He took her hand and squeezed it hard. "You have to run, and hide. Don't stop, don't look behind."
"Doctor-"
"I will be fine. I think the Old Girl loves me enough to deadlock this door, and nothing should enter. But if I'm wrong, it will be dangerous and I don't want you to be here if it happens. I want you safe, Clara, because I…" -he stopped and shook his head lightly- "…you're very important to me, Clara. Much more than you think."
Her heart stopped. Did he mean…? No. No, he meant that she was his companion, for sure. It couldn't be anything else.
The TARDIS started to quake insistently and with increasing intensity.
"You must go, Clara. Leave now, it is a matter of seconds before we land."
"I-I don't want to leave you" she uttered, voice a bit broken.
"You must. Go."
"Doct-"
"I'm glad you already like this new me so much, Clara, but I thought you were the one who listened to me. Don't disappoint me now."
"You said it wasn't safe to wander off."
"True, but if something enters in the TARDIS it will head right here. The Old Girl suddenly deleting rooms and changing corridors could be a difficulty, but maybe it will also help you run from whatever enters. Now go, I can't stay… be awake for lo-"
They heard a loud crash, and the walls finally stayed still.
"Go. We landed. Half crash-landed, I think. Leave, you must be as far as possible from here."
The Doctor gave her hand a last squeeze and let her get up. Clara glanced at him one last time.
"Leave," he whispered, then he his eyes fell close and he laid still on the bed.
Clara understood he had passed out. He needed that sleep. The least she could do was letting him rest without worries, listening to him. The girl took a deep breath and opened the door.
~oOo~
After at least two hours wandering in the TARDIS, without a single clue on where she was as corridors kept changing and rooms kept disappearing, Clara calmed down a bit. She had been anxious and hesitant at first, but now, everything considered, things weren't going too bad. The ship was silent, no strange terrifying noises or other things that could make Clara suppose that something was wrong. The Old Girl was also behaving relatively well: the lights were still on almost everywhere, she had found only three blind alleys, and only one holographic lion.
Her steps the only sound in the empty corridor, the young human arrived at a spot where the lonely corridor parted into three. Clara spent a second to decide if she should go straight on, turn right or turn left. She shrugged, and turned right. The way got zigzag. She had to turn right, then left, then right again, then go straight on for a long while and finally turn right: Clara sighed with disappointment when she found just a wall. Dead point. She inwardly cursed the TARDIS and turned her back, retracing her steps.
As the girl got close to the point where the corridor parted, unexpectedly she heard something: a dull tump far away in the ship, which sounded incredibly similar to a door banging. Something being hit. The noise vibrated through the TARDIS's walls again and again, growing louder and louder, then suddenly stopped. At the point where Clara had turned right at first, she froze, utterly frightened. She was now distinctively hearing voices. Voices. Clara shuddered: if a simple noise could be the TARDIS fixing her face, voices couldn't. Voices was definitively bad.
The Doctor wasn't wrong.
Something could enter.
Something had come in.
Clara pressed her body against the wall in a vain attempt to feel safer, the cold metal sending chills down her spine, as she heard the voices approach.
They became closer.
And closer.
And closer.
The broken whispers became phrases, spoken aloud and clear by metallic voices.
The phrases became shouts, yelled with anger and hatred.
'It can't be.' Clara thought.
But she knew she was wrong. Her back slipped down the wall and she pressed her knees close to her chest.
"Explore. Explore. Everywhere. The Doctor is near!"
'Not them, please. Not them.' Clara begged, to no one in particular. To anyone, in fact. Whoever could listen. Tears began to roll down her cheeks.
"The Doctor is our enemy. He must be defeated!"
"Please. No." Clara prayed one more time, her voice a broken breath, knowing it was useless. There was no mistake. No other possible explanation. The Doctor had said, those devices capable of detecting regeneration energy were popular in the Time War… and there was no way to misinterpret that shout, that battle cry, that single exclamation filled with a hatred that had lasted centuries… the same word repeated over and over and over…
"EXTERMINATE!"