Survivors
The key slides perfectly into the lock, and you collectively breath a sigh of relief as the heavy door slams closed behind you, effectively cutting off the hissing of the escaping gas. God knows what kind of gas that was, but you didn't fancy hanging around to find out!

Now you're inside the office-room - it is poky and small, the furniture and lockers taking up much of the room inside. There are six lockers, as mentioned in the previous description, and one of them is slightly battered at the edges - its door almost hanging open. Within the office-room, there are four items.

What will you do?