Hall of Infinite Doors

The features of the hospital hallway have changed little in the few hours it's been since you've seen it, but the shadowy night lends it a new malevolence. The track lighting is dim but present, making the white walls stand out brightly against the blackness outside. You can see down your hallway, past two ruler-straight lines of doorways on your left and right, both ending at a T-junction and a fire door. The elevator bay, the only place in this dim hallway that anyone cared to carpet and decorate, unloads almost right in front of your doorway. The nurse's station is similarly nearby: a single white desk with a flickering computer and heaped piles of notes and ledgers, currently unmanned. There is no sound, save for the distant hints of other peoples' nightmares and the mechanical hum of fluorescent lights...

... and, suddenly, a friendly chime. A panel above one of the elevators lights up, and the doors beneath it begin slowly to open. You chirp in surprise and quickly shut your door just before whoever it is can see you. You hear a heavy tread and feel the rumbling of a hospital cart pass before your doorway and trundle off into the distance, punctuated by the hiss of the elevator doors latching shut.

That was close. Lucky thing you decided to be cautious - otherwise you might have run right into that guy.

You open your door, give the hallway another careful peek and decide the coast is clear. So long as you run into no other industrious night staff, you can explore the hospital at your leisure.