Author's Note:

Does anyone else think that Boo from Monsters Inc. could be a younger version of Clara Oswald? I do and that's what inspired me to write this.

I'm writing this as though the two worlds have collided and neither has any knowledge of the other. In other words, the Monsters Inc. film does not exist in the whoniverse (well, my whoniverse at least) and vice versa.

From Boo's point of view, the story is set after her door has been destroyed and she is still waiting for Sully to visit her again. While from the Doctor and Clara's viewpoint, it's set some time after the Name of the Doctor. Hope this helps to place my story.

Anyway, I'll shut up now and leave you to read it. Enjoy! :)

No matter how long she travelled with the Doctor, Clara would still be full of joy whenever she visited a different time or place. The Tardis made the whooshing, groaning noise that signalled their arrival and Clara headed towards the doors with a grin on her face.

"Oh." Her face fell as she opened the doors to see black in front of her. It took a while for her eyes to adjust before she realised that it was another door in front of her surrounded by clothes.

"What's wrong?" the Doctor asked.

"We've landed in a wardrobe. And I don't mean one that's going to lead to Narnia. It's just a plain, ordinary wardrobe." Clara said as she closed the Tardis doors again.

The Doctor checked the scanners as though he didn't believe Clara. Then, he walked to the Tardis doors to see for himself. As he opened them, he let out a gasp of surprise. The wardrobe door had opened and a little girl with pigtails was standing there.

"Boo!" the little girl squealed happily.

The Doctor, already a little surprised, was about to pretend to the little girl that she had scared him. But, then she started to cry. He panicked. He wasn't really good with children this age. Babies were fine as he could speak baby and after meeting Angie and Artie, he felt a bit more confident in dealing with teenagers. So, the Doctor did the only thing he could and called for Clara, who was brilliant with kids of any age.

The Doctor didn't actually have to call Clara. As soon as Clara heard the crying, she instinctively knew she was needed. She peeked out of the door to see what was happening.

"Oh my stars!" Clara exclaimed before she collapsed.

"Clara!" The Doctor turned back as he heard her fall. He quickly checked her pulse and then was unsure what to do next. His head flipped back and forth between the crying child and his unconscious companion. His 27 brains had quickly deduced that Clara would be fine, she had just fainted. So, he knelt on the floor and turned his attention to the little girl.

"Not Kitty," the little girl kept on saying between sobs.

"Kitty?" The Doctor questioned.

"Kitty. Boo. Kitty not here."

"Shhh, it's alright. Do you want a jammy dodger?" He felt Clara stir beside him before she fainted again. He felt in the pocket of his tweed jacket for a jammy dodger that he was saving for later. "Now, this is a special biscuit-"

He stopped as he realised that the little girl's shouts were getting louder. Perhaps it was time to leave. He involuntarily shuddered at the awkward questions he would face if he was found in the little girl's bedroom especially as he seemed to have upset said little girl.

"Not Kitty," the little girl pointed insistently at the Doctor.

Although he had no clue who or what this Kitty was, the Doctor was beginning to understand why she was crying. "Ah. This is Kitty's door, isn't it? Kitty isn't here, we are instead. Well, we'll just go then and I'm sure Kitty will be along soon."

The girl stopped crying.

"Well, bye then. Don't forget to eat your jammy dodger before Kitty gets here and eats it instead," he said with a wink. He could have sworn that the girl smiled back at him as he stood up and entered the Tardis. But his mind was focused on other things. Mainly getting them back into the vortex so that he could check Clara was alright.

It was the sound of the Tardis dematerialising that made Clara wake up. The Doctor rushed over and hugged her tightly.

"Clara, are you alright?"

"Is the little girl OK?"

The Doctor smiled. Typical Clara, always thinking of others before herself. It was one of the reasons why he loved her so much. "Yeah. She was just upset that we weren't her Kitty, whatever that is. But, that's not important at the moment. You are. Why did you faint?"

Clara responded with a question of her own. "Did you notice anything familiar about that little girl?"

The Doctor shook his head and looked very perplexed. Clara took her phone out of her pocket and began searching for a photo.

"She's the spitting image of me when I was about three."

The Doctor's mouth dropped open in shock. Clara had found the photo and held it out so the Doctor could see. The resemblance between that little girl and young Clara was uncanny. Why didn't the Doctor notice that before? After all, he had seen Clara at various points throughout her life.

"No way!" He exclaimed. "Are you- is she- I mean... she can't be... is she?"

"That's the thing. Kitty doesn't ring any bells and I definitely would have remembered the Tardis arriving in my wardrobe. So, that means that she isn't one of my echoes."

"But, that's..."

"Impossible!" They both said with a laugh.