Fire door key
"Unlocks fire doors on the first floor of Wing Court."
— "You" upon examining it.

After you meet the White-Faced Man for the first time, you will find the key inside a soda can that he left behind. Return to the hallway you came from (Wing Court 1F, North) and it will unlock the door to your left. In the new stairway (West Fire Exit, 1F), you can also use it to unlock the large door on the right. "You" will throw away the key once both doors have been unlocked.