500 word Story Idea

StoryIdea
My story begins with a main character tying their shoe laces in a dark room, probably a locker room. They look up and a hood casts a shadow across their eyes. As they leave the room and you see the door close behind them the music becomes more fast pace.
The next thing you see is a quick flash of running legs, the sound of heavy breathing and clothing rubbing. The camera then switches to another view pointing forwards from the ground and you hear the same heavy breathing and watch as the runner volts over the camera and into the shot. Another quick camera change and you’re following the runners head from a side view as steam is breathed out into the cold morning air. As the camera slows down and curves to keep the runner in the shot he disappears down the road.
A second or two after the runner has faded into the darkness you see a shadow flash across the screen and you instantly know something is following them. The camera is back on the runner as he enters a small suburban wooded area, the shadow jumps from tree to tree subtly behind them, the runner is aware of something following him and they speed up. They exit the wood into a street and run parallel with the curb. You see the shadow leaping from the roof of the houses, one to another, the runner stops at a t junction and is breathing heavily they don’t know where to go. Its silent, no noise the music is quite, the breathing is dominant and the person looks up and runs toward a subway bridge hoping to see traffic. They run faster and the music quickens, under the tunnel and up the stairs and nothing, no cars no people no life of any kind, and across the bridge they see the shadow as it walks out from the dark but its blurry and they can’t make it out for the sweat running into their eyes. They see the form start to run again and so does the runner. They run down deserted streets and past lightless shop windows, a thin layer of frost is formed on the window pane.
A crack, they trip, down they fall. Onto the hard surface of the tarmac that lines the road. They scramble to their feet and begin the run again they recognise the streets, the shops the trees. They know where they are and feel safer, they turn a corner and there is the gym, they enter through the main doors and burst into the locker room, the door suddenly slams shut behind them the room is dark and cold and nothing is visible but the scales on the far side of the room dowsed in moon light. As they approach the scales the shadowed form starts walking from behind the door, they have no idea and as they step on the scales and the seemingly weightless needle flies past the numbers the creature leaps, the runner looks up looks into the mirror in front of them as the needle settles they fall to the floor...
Dun DUN DUUUUUN!