A small button turns red while a kind of hum is heard behind thick walls.
With every second that passes the border of the button becomes green and the sound clearer.
Suddenly the shiny doors of an elevator fold sideways and a click is as clear as the sound of the wind coming through the frames.
The cabin seems to move with a slight shake, but it stays in the same place for several seconds.
A small red line is still on the button, before a noise of steel plates ends the silence of the wind, and it is the announcement for the doors to close again.
A girl's voice is heard down an empty hallway, someone stretches his hand quickly, violently, accurately, and the doors are thrown open.