The Doctor's hands moved anxiously across the chalkboard, scratching equations like dusty little mice over its dark surface. His eyebrows were drawn together in feigned concentration while his ears sifted frantically through the cacophony of sounds echoing just beyond his door. The raucous laugh of adolescent boys, the sloppy smack of a couple snogging in a supply closet and the slam of a door and barked reprimand as they were caught. The underlying bee buzz gabble of hundreds of students coming back from the Christmas holiday. He wasn't quite sure what exactly he was looking for but he was certain it was none of these things. Then he heard it, the step of familiar feet, not an exact match for the pattern stored in his memory but close enough to be recognized.
His fingers stilled with the chalk, and it suddenly felt as if his hearts were teaming up to break through his ribcage. The steps were, for a moment lost among the clatter of students, not to be recaptured until they were directly in front of his room. The Doctor felt his back tense as the door was pushed open letting in a draft of intense sound only to be quickly extinguished again as the door slid back into place.
There was a moment's silence then a voice, achingly familiar, said:
"You're not Ms. Ricker."
It freed the Doctor from his self-inflicted paralysis and he turned. She stood not three meters from him her arms clasped about a workbook, her eyebrows noble and dark, pulled together questioningly above her huge lolition eyes, sweet bow lips glistening in a frown. He had not been expecting her to be so similar to Clara, a near photograph echo of his dead love.
He swallowed deeply, perhaps the TARDIS had been right, perhaps this was a bad idea. He had thought he could keep himself detached, had told himself that this was nothing more than a mere checkup -making sure that Clara's echoes, with whom his life was so tightly entangled, were safe- the least he could do for the women who'd saved not only his life but his very existence. However, as he stood staring he knew just how wrong he had been.
"No?" He said finally in reply, "What gave it away miss…?"
"Oswin. Clara Oswin," Said the girl with a look of amused disapproval, a perfect replication of the one his Clara used to give him all those many years ago, his throat contracted sorrowfully.
"Do you know where she is? She was supposed to help me with a maths problem." Clara's echo said.
"Retired."
"Retired? She was only thirty."
"Hmm, well I wouldn't worry about it. Humans are notoriously flaky, always changing their minds, always getting bored, always dying."
The girls eyes went wide and she seemed suddenly unsure of the man before hers sanity.
The Doctor remembered himself then, and switching to his most professional voice asked, "Would you like me to help you with it?"
"I suppose." She answered and shifting her book bags position on her shoulder made her way to the front of the room and the Doctor's desk.
The Doctor, placing himself carefully across from her in his chair waited for her to relinquish the book on the desk before picking it up. In his hands it was warm from where the girl had been clutching it to her chest, he felt a shudder of melancholy and was forced to drop it back quickly to the table. His eyes scanned the open page reading quickly the information then going back to take his time studying the nuances of this young Clara's script. In accordance with his Clara's hand it was small and neat, however, this Clara's writing had a slight childish flourish to it that had not been previously present. Another sharp beat chastened his hearts.
"How old are you?" he asked finally.
"Sixteen sir," she answered automatically.
He eyed her for a moment, rounded cheeks, large eyes, ruddy lips. He would have guessed fourteen as soon as sixteen but he could think of no reason for her to lie. Nonetheless:
"You're a bit young for the Navier-Stokes Equations," It was more than a bit of an understatement.
"I'm clever," Was her shameless answer.
"I remember," he muttered sadly down to the paper.
"Sorry, what?"
"Humans!" he covered up a bit too passionately, "Never bloody listen. I said the vector laplacian term, it's all wrong!"
Young Clara's chin puckered stubbornly "What are you talking about? It's fine." She shot back.
"No it really isn't. The laplacian term is supposed to be the difference between the velocity at a point and the mean velocity in a small surrounding volume. This- this is just… glop."
The girl's eyes lit with an argumentative spark at his words. She dropped her bag on the lino floor and marched around his desk, then placing her hand directly next to his leaned across him to glare at her work. It was a perfectly young naive movement from his new pupil, however, the Doctor couldn't help but to draw parallels back to certain less puerile action of his own Clara and he was struck with the sudden craving to pull the girl down onto his now throbbing lap. Disgusted by this perversity he tugged his hand hastily from the desk and shoved the workbook away from himself so that the young Clara was forced to move from him in order to continue her reading.
After a moment, though, the Doctor found his eyes wandering back towards her to watch as she re-assessed her work. As her hand brushed over the sprawling numbers, rapturous concentration caused the tip of her tongue to curl at the corner of her mouth, and her scapulae, prominent through her school jumper wiggled slightly with the movement of her arm, and her left hip listed easily towards him and the small undulation of her breasts beneath her slightly see-through shirt as she breath and-
What the hell was he doing?! Lusting after a young girl, eyefucking the nearly child of an old love, being weak and whimsical and dumb. He stood abruptly shoving his chair back with a sharp squeak then turning to fain a look of disinterest out the rain speckled window. From the corner of his tortured eye the Doctor saw Clara correct the lean in her stance but she was otherwise unmoved by his sudden departure.
He sighed feeling miserable, this had clearly been a mistake. What had made him think he could keep himself away from this girl when he'd already proven himself incapable of just that with his own Clara? He'd spent months being cold and rude and generally just awful in an attempt to keep her at bay only to have himself give in to his own desperate desire in one moment of weakness. He wasn't going to give himself the chance to make that mistake again. This Clara, clearly brilliant and bold and innocent had no need for him and his mad world. But what about me? asked a small voice in his head, Maybe I need her.
That made up his mind, he wouldn't stay, he couldn't. He would wait out the day then make his exit. Run away in his blue box as he had done so many times before, but this time he knew he would be making the correct decision. He rested his forehead heavily against the window pane and let out another quiet sigh feeling his gut twist like a gnarled old root.
"Bloody… How did I not see that?"
The Doctor turned around swiftly to see young Clara drawing jagged lines across the paper of her work book.
"Clara wait, don't." Exclaimed the Doctor hastening over and lashing out a hand to grip over the one angrily destroying its own work.
She looked up at him startled. The hand he had placed over hers burned in that delightful way that made his extremities pulse and his brain buzz, he knew he should remove it, chop it off at the wrist if he had to, but he imagined the gaping loneliness waiting for him just out of sight and allowed himself this momentary bliss.
"Clara," he said straining to keep his voice neutral, "Don't erase your mistakes, just start on a new sheet, you won't learn anything if you pretend they don't exist."
At that moment the door banged open and a loud voice sounded through the room, "-complete fucking twat ye ask me, said he'd call me mum if… Ooh th' 'ell 're you?"
The Doctor's hand leapt from Clara's as if he'd been shocked. He looked up to see who had spoken and found a girl and boy both around Clara's age staring at him with accusatory eyes. He slipped as nonchalantly away from the echo as he could manage and with a dry half smile answered:
"Doctor John Smith, I'm your new teacher."