John Wilkes Booth just left his horse on the side of the building and it is being occupied by one of the workers. Now he is going to sneak into the theater through the back entrance.
Booth is running under the dark stage so nobody will see instead of running across it and being obvious. After this, he will sneak up to Lincoln's booth where he will not be stopped by any guards.
Thump... Thump... Thump...
John is now in Lincoln's booth and holding a gun right behind Lincoln's head. He then shoots Lincoln and swiftly escapes from the balcony through the door. But, he will soon come back to jump off the Booth and onto the stage.