Actually, you don't see that so much as feel it. Your hair is on fire
again.
You put the key in, and the wall itself opens up for you. You walk
into a large room, currently deserted save for a mechanic working on a
pipe about twenty feet distant. You unsheathe your sword, but then put
it back as the mechanic runs from you. You stroll through the room,
but then see that the thing he was running from wasn't you, but a hot
pipeline with a leak in it.