Author's Note: I noticed my lack of Doctor Who fanfic. That is unacceptable. So this quick thing happened.

Disclaimer: Well, Doctor Who is older than I am and I have stated that I am not Steven Moffat, so I own nothing.

The Doctor knew he had done some good. He had spared his sons from the war. But had he really made the right choice? Would they even know it was him? What if they hated him? What if they hated him for leaving him?

He stands at the door with his hand on the knocker. Then he does knock. He waits for someone to come. Was it ten seconds or ten minutes? Ten hours? Ten days? Ten years? Was he too late? Was he here? Was he gone? Could he have moved? What if-

No, all of these 'What ifs' are useless. What happens happens. It will always be that way. The Doctor stares at the white converse he is wearing. The wind whistles against him. Sigh. No one's coming. The Doctor turns to leave when he hears the door open.

"Yes, sorry about that, I've been a bit busy. Are you here for a case?"

The Doctor has to keep his breathing steady. "Yes, I am here to see Sherlock Holmes."

"Ah yes, come on in, then."

The Doctor follows Sherlock. The building smells like old books and mothballs.

"Oh, you have a case today? That's good. I don't want you tearing up my kitchen again with your experiments again. So who are you, dear?"

"I'm John Smith. And who do I owe the pleasure of meeting?" The Doctor holds out a hand.

"I am Mrs. Hudson. Treat this one nicely, Sherlock. I don't want good people going to waste."

"She's the landlady. Now, what do you have to say? Sit."

The Doctor is ready to tell Sherlock off, but he bites his tongue and sits down. "Well, I saw a blue police box disappear. It was odd. I was astounded, because that is impossible. It defies all logic."

"Did you see anyone entering the box?"

Yes, myself. "I- I saw a man in a leather jacket and a purple- yes, it was purple, I think- jumper. He had short black hair and large ears."

"You have something on your mind. What is it?"

"I saw you look surprised when I described the man. Why?"

"This is not about me, it is about what happened."

"Oh, I don't know. You should have heard a lot about this man. And the box as well. Why did you look so surprised?"

"As I said before, this appointment is not about me, it is about you."

"You're flustered."

"I think we should end this."

"You're starting to get scared."

"I'm not scared. I do not feel fear."

"Your heart rate is speeding up."

"Leave."

"I wouldn't advise that."

"I told you to leave."

"I don't think so."

"And why is that?"

"Simply because I don't fear you."

"I said to LEAVE!"

"You don't feel fear but you feel anger."

"That was not anger."

"I have felt true anger, and no, that was not it, but it was anger."

"It was not anger."

"I see we have a scientist here."

"Pardon?"

"You've got a little lab in the kitchen."

"Yes."

"And a skull on the mantle."

"I do."

"So you care greatly about chemistry and biology. You read a lot. But you read people the best.

"I can deduce everyone."

"What can you say about me?"

Sherlock looks over The Doctor. "You… you… have no limits in what you say."

"I personally think the brown looks good with the white, but everyone has their own opinion."

"And you are smart."

"I suppose I'm smart in human standards."

"Humans are not smart. They make mistakes and scar everything."

"Everyone makes mistakes."

"They fight themselves with no idea of what they're doing. They don't care who they're hurting. They just do what they want."

"Yes. But everyone wars amongst themselves. All species do that."

"What are you suggesting? That there's something else besides humans?"

"Haven't you ever fancied the idea of there being something else beyond the stars?"

"No. It's- impossible."

"No, not really. But you'd know all about that, wouldn't you?"

"What, take an interest in useless knowledge?"

"Space is not useless! It is beautiful!"

"How would you know?"

"I've been in space! I've seen the wonders and the terrors of life in the stars, and wars that you could never imagine in your worst nightmares!"

"That is not possible. There is no life beyond the Earth and there never will be."

"So narrow-minded! I was hoping you'd end up more open-minded, Sherly."

"Don't call me that."

"Why not?"

"Just don't."

"You remember!"

"I remember what?"

"You remember me. And what I used to call you."

"I don't know you."

"Your brother- Mycroft- might remember more."

"Why would he?"

"He was older."

"When what happened?"

"When I had to leave. But Mr. and Mrs. Holmes were nice, and I'm sure they raised you right."

"Excuse me?"

"You're excused. Now, I know your flatmate John will be here any minute."

A door opens downstairs.

"I wish I didn't have to leave you two. But I'm sure you dealt with the ghost pains well."

"Ghost pains."

"You know, where you've felt like there was a heart or something pumping in the right side of your ribcage. Where it should not be."

Sherlock is silent.

"And I know why. Have you ever wanted to know why you felt something that wasn't there?"

Sherlock is still silent.

"It's because you're not human. And neither am I."

"No. That's impossible."

"Two heartbeats. That makes you Time Lord: two hearts."

"Do we have any cases- Sherlock?"

"John."

"I think now is a good time to go get milk."

"Yes."

John exits.

"You cannot have two hearts. It's scientifically impossible."

"Then listen to this." The Doctor takes a stethoscope.

"What do you hear?"

"T- Two heartbeats."

"Yes."

"That is not possible! You cannot be real!"

"I may not be human, but I am real."

"You are not human."

"How would that be?"

"You are my son."

"No I am not."

"You are."

"I am not."

"Let me show you."

"Show me what?"

"Something."

"What?"

"I know you'll come with no problem. You are too curious for your own good."

The Doctor is right. Sherlock follows him out of the flat and to a blue box. They don't go in.

"You were telling me about this box. But who is the man you were talking about?"

"That was me! This is where it gets complicated. So, I am a Time Lord, and whenever I get a fatal injury, I regenerate. So I look completely different. And I get a brand new personality to go along with that new face. Unfortunately, I don't forget memories."

"So you just live forever. You never die."

"No. I am the last. Except for you and Mycroft. I managed to save you from the Time War. But technically I am the last, as you two are human for now."

"We cannot be human if we are 'Time Lords'."

"Sometimes Time Lords can turn themselves human."

"You forced us to be human."

"I had no other choice. I am so sorry, Sherlock."

"You forced us to live as a different species!"

"It was either that or let you die! I couldn't go through that."

"So you left us."

"You're alive."

"So I can remember if I go through that process again."

"Yes. You really want to-"

"Yes."

"Okay. Welcome to the TARDIS!" The Doctor pushes open the door of the TARDIS.

Sherlock stares at the vast space of the inside of the TARDIS. "Dear lord." Sherlock breathes in deep breaths.

"I know! It's bigger on the inside!"

A few hours later…

"SHERLOCK! WHERE ARE YOU?" shouts John. He looks around the flat. Had Sherlock run off again? He could never stay put for five minutes.

"I GOT MILK! SHERLOCK, YOU BETTER-" John is cut off by the arrival of a blue police box appearing in the living room.

"SHERLOCK, ARE YOU GOING TO TELL ME WHAT THIS NONSENCE IS?!"

"Hello John." Sherlock opens the door.

"You're in the TARDIS."

"Yes. Isn't she beautiful?"

"I guess so. But why are you in the TARDIS?"

"I am a Time Lord. Isn't that right, dad?"

"Yes!"

"Isn't that the man that was here with the case?"

"Hello! I'm The Doctor!"

"Hi?"

"So I'm here to ask you: Want to join us?"

"In the TARDIS? Is this real?"

"Yes to both."

"Yes. I want to join."

"Come on, then. Even Mycroft is happy. We haven't got any time to lose."