You didn't mean to go in. Youd found the research facility abandoned, and, having no idea what it was, you'd went in. Maybe it was a abandoned hospital or something, and wouldn't that be cool? You found a large door and twisted the handle to open it.

Then the 200-inch concrete door closed behind you. The ward in front of you had cots strewn everywhere, blood on the walls, and flickering lights. Total horror movie type.

You tried clawing at the door, and it wouldn't open.