As the TARDIS stopped, the doctor straightened his bow tie, puzzled. "Where have you taken me, Old Girl?" he muttered as he looked at the co-ordinates "Earth, London, 1934? Why here?" He walked out of the doors of the TARDIS, only to see himself in a nursery with a woman in a brown two-piece suit with a red bow tie rummaging around in a carpet bag.

….

Mary Poppins had been readying for her day off when she heard a grinding sound coming from behind her. "Michael, if you don't stop that racket I will not take you to the park with your sister tomorrow."

When she turned around she stumbled thinking 'There is no way he could be here.' In front of her was a Type 40 TARDIS, a museum relic. She backed up a relatively safe distance and began to rummage in her carpet bag for her umbrella.

"Um, excuse me. Sorry to pop in like this, but where in London am I?"

She stiffened, recognizing the voice. She turned around as she said "John?"

"Mary?"

She took one look at him and said "You are with the Doctor?"

…..

The Doctor stiffened as she recognized him as a Time Lord. "How did you?"

She pointed at the TARDIS "She's a Type 40 TARDIS. And the Doctor leaves the breaks on."

"But that's the fun part." the Doctor whined as he walked over to Mary, hugging her "I thought I'd never see you again." he kissed her before looking into her eyes, trying to see how much older she was.

"What do you mean? Never see me again? What did the Doctor tell you?" her eyes were full of concern for the man that saved her life when she first came to London.

"That all of the other Time Lords were dead?"

"I never involved myself in the Time War."

"Oh. But I… He saw your TARDIS destroyed at the Medusa Cascade!" the Doctor lied, trying to sound like a gullible fool.

"Wait… where is that idiot? He should be out here, where is the insufferable git with his ascot?" Mary walked towards the TARDIS, brushing past the Doctor.

"He hasn't worn an ascot for three regenerations." the Doctor frowned, thinking of how to explain that he was the man she had just called an insufferable git.

"Oh? How would you know that?" she turned back to the Doctor with a frown.

"I'm the insufferable git?"

The silence was almost palpable after Mary slapped the Doctor.

"Ow!" the Doctor rubbed his now red cheek "What was that for?"

"You lead me on. I thought that I was the last of my kind. Then you tell me that you are the Doctor?" Mary Poppins was mad, mad enough to wish that she had more strength to actually cause the Doctor's face some damage.

"In my defense, if I had you would've just done what you did. Ow! That really hurt!"

"Oh, shut up. I didn't punch you in the nose like I would have done in my last regeneration."

The Doctor winced "Yeah, I'm very glad you aren't as prone to punching me as you were last time we were together for more than three days. Blimey, you were a firecracker."

"And you were an idiot!" She turned towards her bag and said "And you destroyed our planet."

"Rassilon was going to destroy Time itself! You would have done the same if you had been in my place!"

Mary paled when the Doctor stopped talking "Go away, Doctor. I thought you were just a man named John Smith. Apparently I was wrong."

"But"

"GO!"

The Doctor walked back to the TARDIS and changed the location to a nearby park. He walked out and sat on a bench. He had sat on this bench and laughed with Mary Poppins after they'd escaped a small invasion of Sontarans in the year 1900.

~Flashback~

They laughed together as they sat on the bench as it began to rain, enjoying the feeling of being drenched to the bone.

Mary sneezed and the Doctor put his coat on her shoulders "Come on, let's get undercover." He held out his hand.

She took it and opened her umbrella. The Doctor yelped as they flew above the storm and landed on a solid cloud that had a small house on it. "Come along, John."

"Oh my god. She's the Nanny. Ok. Best not tell her who I am then."

"John!"

"I'm coming!"

When he walked in, he found himself saying "It's bigger on the inside."

"Oh, yes. Would you like to travel with me?"

"Who are you, really?"

"Mary Poppins."

"No. Really."

Mary sighed. "I am a Time Lord, an alien, named the Nanny. My planet was destroyed by another Time Lord called the Doctor. I don't know why he did it, but he did. So now I have to stay here on Earth and watch over certain children so they grow up to become better people in society."

"Alien?"

"Yes. I have two hearts."

"Oh."

"Are you afraid of me?"

"No! It's just… I don't know if I can handle all this. May we please go back to the park?"

Mary's face fell. "Alright. We'll use the stairs this time."

They walked down the circular stairs in silence, each deep in their own thoughts. Mary thought that maybe he wasn't ready for being told that her cottage was actually a time and space machine. The Doctor was worried that if he told her she'd hate him forever.

Once they returned to the park, the Doctor turned to Mary and said "I had a wonderful time… But I have my own adventures to have. It was fun, but I can't do this."

Mary said "Alright. Just take good care of yourself." They shared a chaste kiss before Mary walked back up the stairs and the Doctor walked to the alley nearest the park, where he entered his TARDIS, and flew off to give River her Sonic Screwdriver.