I need this for a book I’m writing. A lot of people know about the existence of the room I’m talking about, but almost nobody has access to it.
I need this for a book I’m writing. A lot of people know about the existence of the room I’m talking about, but almost nobody has access to it.
The room is filled with a deadly gas. Either it is built so that it vents into the room naturally from deep under ground, or a diffuser is periodically refilled by whoever controls access to the room.
The McGuffin is the antidote to the gas, which you must obtain and administer before entering.
One way of getting a very localised danger like this would be to put it near radioactive ore deposits? You can only go in with a lead shield, and have to angle it correctly