"I'm the Doctor and that is Clara" the strange man motioned between them.
"You are a doctor? I don't see your medicine bag. And there are no herbs around here that you could gather." Merlin was sceptical, he knew what doctors or physicians, as they were known in his world, looked like, Gaius was one of them. To become one took years of studies and this man looked too young.
"No, no, no, dear wizard. I'm not a doctor, I'm the Doctor. That is my name. Well, that is not really my name but even she doesn't know my name, so why should you?" the man pointed at Clara. "And it actually makes no difference to you, so just call me the Doctor, everyone does. Well, not everyone but I don't suppose you would like to call me sweetie. And I wouldn't like it if you called me sweetie either. Actually, no one calls me sweetie anymore" the man started to ramble again but a look of sadness passed his face and drained his seemingly endless energy after the last sentence.
"Are creatures like this common in your world?" Arthur asked wanting to know more about the strange place they had come to.
"No, didn't you hear, they come up every 2849 or so years. And what do you mean "your world"? Aren't you from this planet? You look like humans, aren't you from earth?" Clara had questions of her own.
"What is a "planet"?" Merlin wanted to know.
Arthur and the stranger who had recovered and looked as lively as before started to speak at the same time.
"We are from earth, but we came from another world through a hole-"
"A planet is like a large gathering of all this different stuff and it is very cool-"
Both men stopped and looked at each other.
"Wait, you came through a portal? Of course, you are from earth, just from another parallel earth." the Doctor exclaimed.
"Parallel earth?" Clara, Merlin and Arthur asked for further explanation.
"You see, this is our world, it is wibbly-wobbly and everything that happens here influences it." The doctor held up his hand and wiggled his fingers. Then he lifted his other hand and placed it opposite the hand without touching it. "And this is a parallel world – things are pretty much the same, because of the, eh you wouldn't be able to pronounce or understand it anyway, let's call it "magic". So, there are trees, ground, rivers and so on in both worlds. But also because of this "magic" the worlds are different in some ways." And he started putting the hand in a fist and releasing it.
Then Merlin put his hand near the Doctor's and started turning it around. Now the three hands formed a triangle without touching each other.
Arthur understood immediately – he had spent very much time with Merlin. One could even say their mind worked alike – they were like two sides of a coin.
The Doctor looked a bit longer until he too understood what was meant.
He turned to explain it to Clara but was surprised when she said "So you two have already gone through one parallel world before coming here. This is the third world you have been in."
"Clara, you clever, clever girl!" the Doctor patted her on the head.
"But it is pretty unusual, three parallel worlds being connected with a portal. Show me where you appeared at." he continued.
As they turned around and started walking back he took out a small stick with a glowing light on the end of it.
"What is that?" Arthur asked pointing to the stick while leading the way back.
"That's his sonic screwdriver, pretty useful, you'll see. Don't worry if he swings it around very much, he likes to move a lot." Clara explained.
They reached the place where Merlin and Arthur had appeared and the Doctor waved the screwdriver around with a concerned expression.
"There was definitely some disturbance here but now it is gone." he said and turned the screwdriver to Merlin who immediately took a step back and assumed a defensive position.
"Merlin, calm down, it's just a stick with glowing light." Arthur tried to calm his friend.
"How do I know we can trust them?" Merlin was still doubtful.
"Merlin, they calmed down a giant blob when we saw them, you yourself helped them. And if they wanted to harm us they would have done it long ago." Arthur said.
It calmed Merlin and he lowered his hands. The Doctor sighed.
"I know I'm a powerful Timelord with two hearts but when a legendary wizard points his hands at you one of your hearts can't help but skip a beat. I mean, I just got threatened by the legendary Merlin!" the Doctor grew more and more excited with each word.
Merlin stood confused, he wanted to apologize but it looked like there was no need. Besides, it was the first time anyone had been honoured by being threatened by him. He didn't know how to react.
"What is a "Timelord"?" he asked, turning to no one in particular.
"A race of aliens, very ancient, very wise. And very extinct – he is the last of his kind." Clara looked at the Doctor in sympathy. The Doctor didn't seem to notice, the gears in his head had started turning.
"They used to travel all of time and space, now it is just him alone." Clara finished her explanation. Merlin turned his gaze to the strange man, he couldn't even imagine being so alone – traveling for centuries alone, having no family left alive. He shuddered even thinking about it and KIlgharrah came to his mind. He thought about how the Dragon and the Doctor had much in common – they were both wise, though the Doctor seemed to hide it under his rambling, ancient and alone.
Meanwhile the Doctor too seemed deep in thought. He had started walking with fast steps around the remaining three and mumbling to himself.
"Does he do that often?" Arthur whispered to Clara.
"Yes, that is his way of working out a problem – he is a mover. Just wait and watch." Clara said with a smile.
Then suddenly the Doctor stopped. "Of course. Oh, it was right there. Frank, that's why he came up a year earlier! Let's go, I think I know how to get you home!" he exclaimed and started walking quickly in one direction.
"Wait, Doctor, you don't know why we entered the portal." confused Merlin shouted after the Doctor.
"Tell me on the way." the Doctor yelled back and motioned for them all to follow.
While walking Merlin stayed next to the doctor and relayed all of the events – the butterflies, the dogs, the forest, Sam and Dean, the abandoned village. The Doctor just listened and concentrated on leading the way time by time giving a sign of understanding.
"And then Dean and Sam decided to stay and research and send Cas if there were any news." Merlin finished his story.
"How foolish, don't they know that the best research is by jumping head-first into everything? I have read every book, well, every book of importance, and I can tell you, personal experience is the best." the Doctor said.
"I wouldn't recommend jumping head-first into everything, I could have avoided a great mistake if I had done more research before acting." Merlin sighed.
"You mean Morgan le Fay, don't you?" doctor said.
"Well, she is called just Morgana in our world, but yes." and Merlin told that tale too.
"Actually, it sounds like you couldn't have done anything. Seems like it was a fixed point in time." the Doctor said after hearing all Merlin had to say about his friend-turned-enemy-turned-prisoner.
"What is a fixed point in time?" Merlin asked though he had an idea.
"You're smart, what do you think it is?" the Doctor looked at the warlock.
Merlin scratched his head. "Well, you told us how the big things in all worlds stay the same... So that means that some events have to happen to form the basis of the world…" Merlin thought out loud. The Doctor urged him on, he always enjoyed watching people figuring things out, how they slowly moved towards the right answer; it was fascinating for him.
"So the fixed points must be these events, the big events that shape the world!" Merlin exclaimed.
The Doctor applauded his new friend. "See, I knew you could work it out!"
Meanwhile Arthur and Clara were starting to get tired, they had walked for a long time already. So the king told Clara the shorter version of their story.
"Ok, we are getting near. But I guess you can see that." the Doctor shouted at Clara and Arthur who had sunken into a conversation about their friends. They had surprisingly discovered very much similarities between the two – the need to take care of things by themselves, always saving them, the strong sense of what is right and what is wrong. Even their appearance bore some similarities – both the Doctor and Merlin were tall, thin and had noticeable cheekbones.
Hearing the call Clara and Arthur paused the conversation and properly looked around. And stopped on the spot.
Merlin looked around too and saw a small bush in a distance. "There is nothing else around" he thought. And by nothing he meant really nothing – there was no colour in a large radius around the bush.