Explanation

I was in a dilemma.

On one hand, I didn't want to go to the church, on the other hand, jumping 10 hours into the future in Tardis's timeline was risky.

"I will see you in 10 hours then," I said and teleported not waiting for a reply.

The doctor was left standing there alone, he shrugged.

I opened my eyes in Tardis, 10 hours in the future of it, and it was empty.

I walked towards the door and opened it, outside was snowing as a chill wind hit me in the face, I could hear screams and explosions as a war waged on. The town outside was on fire...

Metal Cybermen, Daleks, and other things attacked everyone, a laser shot even passed my face making me gulp.

I returned inside Tardis, closing the door. Then I teleported.

Inside a building, the Doctor was working on a wooden dog. He had become an old man now. He had been protecting this town from aliens for many years.

I appeared right in front of him, I saw a girl talking to him and she turned to look at me with surprise.

The doctor on the other hand seemed excited as he stood up, "Ah, it took you centuries to come! I thought you said 10 hours... Maybe I heard wrong..."

He suddenly stopped and muttered to himself, "So this is how she felt..."

He noticed the girl's look and introduced, "Clara, this is the Traveler, a most ancient existance."

I was confused by what he said, he noticed that.

"I figured it out, it took decades but I did it! I solved the mystery..." He laughed joyfully.

I realized that the analysis must have been completed by the Cyberman's head he had, many years ago outside the Tardis. Since I teleported to Tardis that was 10 hours in the future in its timeline, it actually brought me here, centuries in the future of the doctor.

The results of the analysis must have been a mystery to the Doctor and he had spent his years in this world trying to figure it out. He would have remained here if I had not come anyway but he had something to do at least.

Clara didn't seem to care, "Doctor now is not the time..."

She was interrupted by him, "It is precisely the time, this puzzle took me decades to crack. Now it's time I reveal it."

He turned to me, "The result of the analysis was a puzzle, one so difficult I could barely understand it! But eventually, I solved everything."

I was getting impatient, "Doctor, tell me."

He began walking in circles as he talked, "I first thought the Space-Time anomaly on your shoulder was a mark but no, no, no. It was a gateway. A singularity of sorts... And it's connected to the 12th Dimension."

He paused for a moment, something like a bomb went off in the distance, "I theorized that It was an item but that couldn't be... After calculating it, I figured it was a part of your body, that was the only explanation why you could live with such a thing; I mean, the energy it gives off alone is enough to wipe out galaxies despite being extremely subtle and undetectable..."

He looked at me with a smile, "So the only answer I have is this; You are the 12th dimension, at least its mind, that has made a gateway and formed a body. For some reason, you have forgotten your memory or perhaps, you never had a memory, to begin with..."

I was a bit shocked.

A very nearby explosion shook the place, Clara held the Doctor's hand. "Doctor..."

A loud sound came from the sky, "The Doctor is required!"

He sighed, I shook his hand, "Thank you, really."

He nodded and began talking with Clara.

I made some distance and looked at the glowing crack.

The doctor soon walked up while Clara approached me, "You need to save him!" She urged me out of nowhere.

I looked at her with surprise, "How?"

She answered with a question as if it was obvious, "You are the 12th dimension?!"

I became silent for a moment then pointed at the crack, "Talk to that."

She nodded and went by the crack, I ignored her and walked outside.

The Doctor was on top of the building in the bell chamber.

Suddenly, a crack similar to the previous one opened in the sky and some golden energy entered the doctor's mouth.

A super regeneration saved the day.

I smiled and teleported back to my room.

Later that day, the Doctor searched for the Traveler for hours but could not find him. He was disappointed because he was one of the only mysteries the doctor could not fully unveil or even understand, he wanted to talk to the being.

He sighed as he felt his time had come, the clock was striking twelve's. Perhaps they would meet again...

I looked at my reflection in the mirror and felt how surreal the situation was.

With a satisfied expression, I sat down on the couch.

'At least I know a general idea. I think the 12th dimension tried to do something but failed and that lightning was the result, it hit me and the 12th dimension became me. But since it had no memory yet, it was basically a blank being. I am the 12th dimension with the memories of this person or the fusion of both. No matter which, I don't really feel different before the lightning hit me, I only have a new power.' I thought and relaxed my tired body.

It had been a stressful few hours.

'What do I do with my life now? Studying? pff... Working? Haha... What would someone else do if they had my ability.' I thought as I looked at the ceiling.

'They would go on adventures, and have fun.' I answered myself and smiled. 'No matter if it's riches, power, or beauties, all are within reach, just a thought away...'

But when I thought back to the last place I had been, the laser attack appeared in my mind, 'It's dangerous and I have no idea what will happen if I die...'

I was feeling doubtful about what to do. I wanted to go on adventures in fictional worlds but the danger level was making me pause.

Then I remembered a certain way to become immortal and undying. I smiled confidently and closed my eyes, 'Time to teleport.'