You were in a restricted laboratory. You manage to make your way through a hallway, that is also an office. You can tell because there is a desk with a tall office chair, weirdly turned the other way from the desk. But suddenly, it rotates by itself, and it's revealed to have no one sitting in it. A brief seconds of silence pass, and you suddenly felt something immediately touch the back of your head. Something like... a firearm's barrel.

"Hands in the air. HANDS IN THE AIR."