A/N: This is an idea that just appeared in my head, and I thought I'd share it with all you lovely people. I don't own Doctor Who. Enjoy!

The Doctor had been contained in a glass tube while Clara had been tied to a chair in front of the tube.

Flashback:

The Doctor had previously been trying to destroy a machine that turns people into spirit. But he'd accidentally set an alarm off, and guards had immediately flooded the room and put the Doctor in the glass tube which was hooked up to the machine, while Clara had been tied to the chair. The project manager had set the machine on a timer for 1 minute.

Present

30 seconds remained, and the Doctor had no way of stopping it. Clara just sat there in front of him, powerless to help her best friend. She just sat there watching the timer tick down to zero, when the Doctor would be turned into spirit.

Suddenly, the Doctor's face lit up. He'd just thought of an idea. "Clara, you know in about 25 seconds I'll be turned into spirit?" asked the Doctor impatiently.

"Yeah, why?" answered Clara nervously. (It should be pointed out that Clara hasn't been gagged, only tied to a chair.

"I won't be solid, which means I won't be able to stop them, unless..." the Doctor trailed off, hoping Clara would realise what he was referring to.

"Unless what?" asked Clara, eager to help the Doctor in any way possible.

"I'll need to borrow your body just to allow me to have solid form again while I destroy the machine and retrieve my body." said the Doctor. He saw Clara's face turn into one of disgust and horror, and realised that she wouldn't let him.

Clara sat there, amazed and horrified at what she had just heard the Doctor say. She wanted to help him in any way she could, but him borrowing her body was a step too far. But she could trust the Doctor to behave in her body, but still didn't like the idea of him controlling her every movement. Eventually, she gave in to her instincts. "Ok Doctor, but you must behave or else you are going to be in BIG trouble." she eventually replied. The look of relief and happiness on the Doctor's face was enough to make her realise that she had made the right decision.

"Oh thank you, Clara, thank you, thank you, thank you, I promise to behave, just let me take the machine back to the TARDIS and I'll leave your body then, is that ok?" he asked, evidently pleased that Clara could trust him.

"That's fine, Doctor, just stay safe." said Clara with a smile, just as the timer hit zero.

There was a blinding light, and Clara saw the Doctor just disappear in front of her. She was stunned, and she knew that any moment, the Doctor would just walk into her body, but she didn't care, as long as the Doctor was safe, she had a feeling of happiness inside of her, and that was the last thing she felt for herself for a while.

The Doctor opened his eyes, and saw that he was still inside the tube, but when he looked over at Clara, she was looking at the tube in astonishment. He waved, but Clara showed no signs of recognising him at all. She started looking all over the room, obviously looking for him. He walked straight out of the tube and over to Clara. He waved his hands in front of her face but still didn't get a glimpse of recognition. He saw her smile, and without any hesitation, jumped into her body.

When the Doctor opened his eyes next, he looked down and saw himself wearing a red dress with brown ankle boots (if you want a visual image of Clara's clothing, look up an image of Clara in Journey to the Centre of the TARDIS). He saw a pair of breasts on his chest, and every part of his brain wanted to feel them, but he couldn't betray Clara like that, but then again, she wouldn't know, so the Doctor wiggled out of the ropes holding Clara's body to the chair, gave Clara's breasts a light squeeze, and started moving the machine out of the room it was currently in, ignoring the wetness that had developed down below. He spotted the sonic screwdriver on the ground by the tube as he passed it, and quickly picked it up, held it in Clara's mouth with her teeth, and moved the machine out of the room.

20 minutes later, and the Doctor reached the TARDIS, which was parked outside of the research base and went to open the doors, but the TARDIS refused to open the doors for him. "Come on, why are you doing this?" he asked, desperate to give Clara her body back. He heard a sound from behind him, and he turned to the source. He saw an exact copy of Clara standing there, and immediately recognised what it was. "TARDIS Visual Voice Interface, I presume. Tell me, why aren't you letting me in?" asked the Doctor, wanting to relieve Clara from having him inside her.

"Clara Oswald, I cannot let you in without the Doctor being with you as it is a failsafe to stop meddling humans from interfering with any of my controls." the TARDIS Interface said.

"Don't you understand, I AM the Doctor, the machine I have with me now is a molecule de-stabiliser, designed to turn solid objects into spirit. I was captured and placed inside the machine and I was turned into a spirit myself, but before I did, I asked Clara if I could take residence in her body until I can get the machine to give me my body back. I didn't do this without her consent first." explained the Doctor.

"If you really are the Doctor, then answer me this: what do you call me when no one is around?" asked the TARDIS.

"I call you Sexy. Is that good enough of an answer?" asked the Doctor, getting very impatient and uncomfortable being inside Clara's body, although slightly enjoying it as he had been attracted to her ever since he first laid eyes on her, when she was a Victorian, but he tried not to let that get in the way, he had more important business at hand.

"I'm sorry Doctor, I didn't realise it was you, please forgive me, I'm unlocking the doors now." said the TARDIS, and the copy of Clara disappeared, and from behind the Doctor, the TARDIS doors swung open to reveal the console room. The Doctor grinned, and pulled the machine inside the TARDIS.

Once he was inside, he pushed the doors shut and started searching for various cables. 10 minutes later, and he came back up with dozens of various cables and started plugging them into the machine, and then into the console. Once all the cables had been plugged in, he activated the machine. He started the countdown which had been set for 10 seconds and stood in the glass tube which he had managed to drag along with him. He had measured the tube and found out that it was big enough for him and Clara to fit inside once he gets his solid form back, so he had decided to stay inside Clara's body until the very last second, in case he needed to make some modifications to the program. The TARDIS lights started to dim, and that was when the Doctor realised how much of a power drain the machine was, but he was determined to continue, especially when he noticed that the TARDIS was shutting down all unnecessary systems to help the Doctor leave Clara's body, and then it hit him with what the TARDIS had said to him while she thought he was Clara...

Flashback:

"Clara Oswald, I cannot let you in without the Doctor being with you as it is a failsafe to stop meddling humans from interfering with any of my controls." the TARDIS Interface said.

Present

Clara has been right all along, the Doctor realised, the TARDIS does hold a grudge against her, and he just thought that Clara had been taking things the wrong way. There was no failsafe like that; the TARDIS was making it up. He'd have to talk to the TARDIS after this was sorted out. The countdown reached zero, and nothing happened. The Doctor left the tube and scanned the machine with the sonic screwdriver, and found out that the TARDIS didn't have enough power to keep the machine powered enough to complete the process, so he plugged the activated sonic screwdriver into the machine and automatically set it for a 10 second timer, giving him enough time to get into the tube, and as the timer hit zero, there was a blinding white light and when the light had vanished, the Doctor had appeared back in his solid body. He clambered out of the tube with Clara following behind.

"Thank you for keeping my body safe, Doctor, but next time, don't squeeze my breasts." said Clara with a smirk, and she walked off with the Doctor following, stuttering.

2 hours later, and Clara walked back into the control room. The Doctor was off somewhere doing something, and the machine was still there. Clara walked over to the machine and an idea formed in her head. She activated the machine and stood inside the tube. There was a blinding light and Clara was in spirit form. She walked off to find the Doctor.

10 minutes later, and she found him in the library, but as she was spirit, he didn't realise she was there. Clara smirked, and walked into the Doctor's body. When she opened her eyes, she saw she was wearing an old tweed jacket with a bow tie and black shoes. She smirked. "This is what you get for playing about with my body, Doctor." she said, and walked off, feeling the Doctor grow hard at the thought of what she was about to do.

A/N: Now you didn't expect that, did you? What will Clara do in the Doctor's body? Well, I'll have to leave that to your imagination, as I have planned for this to be a one shot only. Please review. Thanks!