In the wall was a small portal, it had always been there, yet nobody had ever seen it, but this day was special, it was the one time in the whole year that the portal would open.
Out of the swirling mists of the portal came a small figure with clothes that had not yet been invented, and a cat which had accidentally travelled with him. The portal was not unique, there are loads all around the world, hidden, but it was the one that the person came through and the person was important, as the grandson of the person who would eventually take over the world, he was supposed to kill him
He did not know he would be killing his grandfather, neither did he know why he had been sent through the portal, all he knew was that he had to kill this person, whoever he was, and that he would only know when he saw him.
He walked down the street, or at least what you might call a street, although it looks a bit like it is made of stars, and then came out in a picture frame in a house, luckily no-one saw him so he continued to walk. He did not know where or when he would stop because he had no idea where he was going.
He walked out of the house and down another road, time slowed down as he moved, nobody near him could even moved because of the slowing effect of the person on the universe, a rip or two in the space-time continuum appeared around him, but whenever there is a paradox or something that needs to be patched up, the time-cleaners do it, they have been known to erase whole lives to avoid the continuum being broken or a paradox happening. The time-cleaners were usually invisible, unless you knew they were there. He felt that the person he needed to find was somewhere above him.
He could not fly because he had lost his wings previously in an accident with a jet plane, so he had to ride the rips, go through a rip and then hope it would come out where he wanted to go. He walked through the first rip and he came out somewhere he had never been before. He went through another and came out in a cinema, he gave up and decided to find some wings, he went back through a portal into his world, and came back with the wings and flew up to the cloud.
On the cloud was a small old man, who immediately shot him with overpowering thought which was quickly blocked by the other man, who hit back with a sad thought to try and kill him. The other person blocked it and shot back with a thought like a gunshot. The other man ducked and hit the man with another thought, killing his grandfather.
The man never existed, neither did his grandfather, the time-cleaners sorted that.