Swamped

"They're not really meant to be latrine covers. They're just supposed to be weights," she says calmly. "We mainly use them when we've got to get a heavier patient out of bed. Tie ropes to the weights on one end and the patient on another, and we can use that to get the patient into a cart."

You find that strange.

"Seems to me there ought to be something lighter that can do the job."

"Oh, there's plenty of other options if you don't mind them catching fire." She takes a glance in the latrine. "Hmm, no beetles at all there."

"There were a few. I put them in a box I found lying around," you reply. "Is fire a big problem?"

"Not a common one, but we had one a few years ago and we decided not to risk it. Even if it means lugging these weights around. All right, we'll put this down. You take that board off, and then we can just push this over the hole."

You both put down the cover. Then you reach for the board.

As soon as you lift it, smoke pours out. You both fall unconscious in moments.

Right. New plan. Get the nurse out of here, get your mask on, get the metal cover on and then have a talk with the wizard about whatever in the hells you just saw.

So first you need to persuade the nurse to leave, preferably without explaining that you think you just saw a vision of the future.