Bill Potts raced across the St. Luke's campus.

Her trainers slapped at the pavement as she wove her way through the massive crowd of other uni students.

Now who's running around like a penguin with its arse on fire? she thought wryly, as she ducked between two jocks, the top of her afro skimming one's arm.

"Sorry!" she called over her shoulder.

The reason that Bill was in such as huge hurry was that she had a paper due – in two minutes. She'd overslept that morning and the Doctor had warned her that if she were ever late on an assignment, he'd stop being her personal tutor.

The truth was, Bill couldn't afford to attend St. Luke's University. She worked in the canteen dishing out chips. She was twenty-six years old, and drifting through life.

She'd snuck into a few of the Doctor's lectures and found herself highly amused by his erratic tangents and overall grumpy Scottishness.

One day, the Doctor had made it apparent that he was aware of her status as a non-student, but instead of having her removed from the campus, he'd agreed to be her personal tutor – as long as she always got high marks on her assignments. He'd even forged paperwork to get her scholarships.

However, the best – the very best thing, well one of the very best things – that the Doctor had done for her was introduce her to the TARDIS his bigger-on-the-inside-looks-like-a-1950s-police-box time machine. The interior still looked like a kitchen to Bill, but she loved the adventures that she and the Doctor had – alongside their sometimes companion Nardole. Bill had faced sentient oil, the Daleks, killer Emojibots, an alien sea monster under the Thames at the Frost Faire in 1814, the Shining Men, ghosts in Edinburgh, and most recently, the Monks.

The best thing that the Doctor had done for Bill – truly – was that he had given her pictures of her mum.

Bill's mum had passed away when Bill was a baby. She'd had no memories, no pictures, nothing to connect herself to the mysterious woman who had given her life. She didn't even have a name.

Learning of this, the Doctor had zipped back in time to when Bill's mum was still alive, and had taken several pictures of her. Seeing those pictures had brought tears to Bill's eyes. Her mum had been a beautiful woman with a warm, loving smile.

Bill cut across the lawn, and burst into the building, crashing through the old wooden doors of the Doctor's office,

The Doctor sat at his desk, bushy eyebrows arched, and his fingers steepled across his mouth.

"Doctor, I –" Bill began, bent over as she panted, drawing precious oxygen to her lungs.

"You're late," the Doctor growled, frowning.

"I –"

"Almost."

The corners of the Doctor's thin lips tugged up into a smile, which alighted his eyes and suddenly he looked like the kind of person who could never be cross or grumpy.

Bill sighed with relief, and fished her paper out of her bag. She crossed the study and handed the stack of papers to the Doctor.

He accepted the proffered papers, leaning back in his chair.

"Have a seat," the Doctor said, waving toward the empty chair across from his desk.

Bill dropped into the seat and blew air out of her cheeks. Watching the Doctor read her papers was the most nerve-wracking thing that she had ever experienced.

She watched as his eyes flew across each page, much faster than a human professor's would. She chewed her nail anxiously, tapping the tip of one trainer on the floor, her whole leg shaking.

The Doctor flew through the essay like a tramp tearing through a burger. Bill could not imagine reading anything that fast and retaining any of the information.

After defeating the Monks – by thinking about her Mum – the world had been restored to normal. All of the statues that had been erected to the creepy blokes were currently being knocked down. The Doctor had taken the opportunity to assign Bill a paper detailing the Monks' invasion and why thinking about her Mum had helped vanquish the mummified things for good.

Bill was still foggy on the details of the whole adventure, but she'd used what little she did remember and what the Doctor had told her to try to explain it as best as she could.

Based on the sour expression on the Doctor's lined face, she had not done well. Bollocks! Bill thought angrily.

The Doctor closed the folder and tossed it down onto the tabletop. He cleared his throat and once again steepled his fingers across his mouth.

"Oh, Bill, Bill, Bill…" he mused, sighing.

"Look, I know it wasn't my best, but -" Bill shook her head, her eyes welling with tears. "Please don't drop me. Doctor. I honestly can't remember much of it. I tried, I really did. All I know is that my love for my Mum was the only thing that saved us."

The Doctor regarded her intensely, blinking his eyes slowly, as if trying to come up with the more intelligent criticism that he could think of.

"Bill, that was –" the Doctor began.

"I know," Bill interjected, holding up her hand. "I'll do better next time, I promise."

"I don't think you can."

"What?"

Bill burst to her feet, nearly knocking the chair over in her haste.

"That was the best paper you have ever written for me, Bill Potts. Well done."

The Doctor smiled grandiosely and scrawled an "A+" on the top of her paper in red marker, circling it.

"Get it!" Bill exclaimed, punching her hand into the air triumphantly. Never in a million years had she reckoned that her jumbled mess of an essay would go over well with the Doctor. I guess miracles do happen!

The Doctor grinned at her enthusiasm and regarded the two framed pictures on his desk. One was in black-and-white of an elfin looking girl with big bright eyes and short dark hair under a leather cap; the other was a beautiful middle aged woman with a sad, winsome smile and reddish-blonde curly hair. The Doctor would not tell her who the mystery women were, except to say that they had once meant a great deal to him. His wife and daughter, Bill reckoned.

"The way you wrote about your mother was very touching," the Doctor commented.

Bill chewed her lip, trying to suss out what to say.

Since her experience with the Monks, she had been thinking even more about her Mum than normal. What had she been like? What had her name been? Would she have been the great mum that Bill imagined she would've been? Would she have been okay with Bill being gay? There were so many unanswered questions in Bill's life that she felt incomplete without the answers to.

'Doctor," she broached, tucking her hands into the back pockets of her trousers.

"Mmm?" the Doctor acknowledged, arching a bushy grey eyebrow quizzically.

"When we first met, you went back in time to take some pictures of my Mum…"

"Yes."

"What was she like?"

The Doctor, swallowed, tapping his fingers on his lips.

"I didn't really get to know her, Bill," he said gently. "I just caught her one day at a street fair and took some pictures."

"Not all of those pictures were from the same day," Bill pointed out.

The Doctor sighed and stood up, running a hand through his curly grey hair.

"All right, I may have visited her more than once."

"And?"

"I became her friend, so to speak. For you."

Bill blinked back tears, imagining getting to actually meet her Mum.

"Tell me about her?" she asked, a tear spilling down her cheek.

"She was…lovely," the Doctor replied. "She was very kind. Extremely brilliant."

"What was her name?"

"Sioned."

"Sioned," Bill repeated, smiling slightly. Such and exotic name! It was, no doubt, Welsh or Irish, but it sounded foreign, maybe tracing back to her African roots.

"That's about it, I'm afraid."

The Doctor stopped at the window and turned back to face his protégé.

Bill looked down at her trainers for a second, and then faced the Doctor again.

"Can I meet her?"

Bill's voice was barely more than a whisper. It was drenched with emotion.

The Doctor glanced out the window, watching the students moving about on the lawn.

In his Ninth incarnation, he'd travelled with a brilliant blonde shop keeper called Rose Tyler. She'd lost her dad as a baby. She had manipulated the Doctor into taking her back to the day of his death and had saved him – causing the Reapers to come forth and threaten the very existence of time.

Was Bill's goal the same as Rose's had been? As much as he had loved – and still loved – Rose Tyler, the Doctor was also aware of how incredibly selfish she could be at times, and yet….had it been selfish for a nineteen year old girl to want to save her father's life?

"It's tricky, Bill," he said, turning back to face her. "You go back to meet her, you get attached –"

"I won't! I mean, I will, but not too attached. I just…want to know her. For so long she's been this mystery to me. I don't want her to be that anymore. I want to have just one day knowing what it's like to have her in my life."

Bill certainly did make a good case, there was no doubt about that. The Doctor felt a pang of sadness in both of his hearts. He often ignored Bill's emotions because she was such an awkward, humorous girl, but he had always suspected deep down, that Bill's humor was just a front, a shield to protect herself from the pain.

"I'd be lying if I said that I hadn't expected this day to come," he continued.

"I am not using you as a means to get to see my Mum." Bill exclaimed, hands on her hips.

"I never said you were, Bill.' He pinched the bridge of his nose, his brain exploring all of the possible ways that this could go wrong.

"Please, Doctor," Bill pleaded, crossing to him, and taking his hand in her own. She stared up at him pleadingly, her round, almond shaped brown eyes tinged with sadness, imploring.

The Doctor sighed and nodded his head.

"Fine. But one day!" He help up his index finger to demonstrate.

"One day," Bill agreed, grinning like a madwoman.

"And there are rules, Bill: no changing the future. You cannot tell her anything that will alter the future for her, or you. Even the smallest thing can cause the most monumental damage to the time continuum.

"I won't say anything," Bill promised, on her tip-toes like an excited child.

"If you muck this up, we're finished," he threatened darkly.

"Of course." Bill nodded emphatically.

"Now, let's get this over with before I change my mind."

The Doctor threw open the TARDIS doors and Bill dutifully followed, her heart light with excitement. She truly felt like she could fly.

At the center console, the Doctor flipped some switches and punched some buttons. The column started to rise and fall as the control room was lit up, the familiar groaning, wheezing sound of the TARDIS engines assaulting her ears.

Bill anxiously waited until everything stood still and there was silence in the TARDIS once more. Well, except for the hammering of her heart in her chest.

"Through those doors," the Doctor bellowed.

"My Mum?" Bill choked out.

"Your mum," the Doctor confirmed.

Bill glanced down at her clothes. She was wearing her favorite outfit: her Prince t-shirt, ripped black skinny jeans, her gossamer green Chucks, and her acid washed jean jacket, complete with all of her badges. That should work for 1990, right?

"Your clothes are fine," the Doctor assured her.

"You can do this," Bill whispered to herself.

Her giddiness nearly overwhelming her, Bill reached sweaty hand out to the latch and opened the TARDIS door. She glanced back over her shoulder, but the Doctor waved her on. Swallowing nervously, she stepped out into the brightness that was nearly blinding. Bloody hell the 90s were bright!