Please post a dungeon room here!

in the room is a crystal sphere on a pedestal. On the wall is a button.

When the sphere is lifted, stone barriers close on all the doors, making exit impossible. A female eleven voice starts to count down from 30.
If the button is pressed, it will reset the count to 30.
Once the countdown goes to zero, the voice goes "thank you, you may leave." and the stone barriers lift up.   

The sphere is a floating lantern that if filled with three vials of oil it will float and act like a lantern. (burns x3 as much oil as a normal lantern)