On the ground floor of my house there are four rooms, including the hallway. My hallway and kitchen connect to each other and when you look down the hallway from the front door, you can see the back window of the kitchen. Then there is the dining room and living room that connect to the left side of the hallway.
Now that you know the layout of the ground floor, let me begin with the story:
It was a regular evening in my house, my cousin and his fiancée were staying in our house while they were visiting London (They lived in New Zealand). Myself, my mother, father, cousin, and his fiancée were all eating dinner in the living room at around 8:30pm. It was pitch black outside at this time.
I was the first one to finish my dinner, so I decided to take my plate and cutlery out of the room and place them on the kitchen bench next to the sink. Everything seemed fine as I edged closer and closer to the bench, but when I placed my plate and cutlery down I froze. I saw something outside the window. It moved extremely fast from the left to the right and was gone in a second or two. It almost appeared to be gliding because it wasn't moving up and down. If you blinked you'd miss it. If my memory is correct it was a humanoid figure and was completely white, but looked to be wearing clothing. I couldn't see a face, just the shape of the thing.
But this is where the story gets a bit freaky. Our garden fence is made of a sturdy wood, quite tall, about 6 foot maybe. There's also a gate of the same height and material that was locked at the time, and the only way to open it would have been to break it.
When the white figure zoomed from the left side of the garden to the right, it disappeared. It went right through the fence that was closest to the window and vanished. It would have been difficult to climb the fence, but still possible. However this would have taken a bit more time than a maximum of a few seconds.
Anyway, I was frozen solid in fear and my only reaction was to run back to the living room to tell everyone what just happened. Instinctively, my cousin ran outside to check that the figure was still on our property, but it wasn't.
Six years later and I still have no idea what the hell that thing was.