You walk into the lab and realize that a thermite experiment has been set up and is about to start. However, it was placed near a really large block of ice. If the reaction starts, the ice will melt and flood the room. If the lab floods, you won't be able to finish your experiment today and won't be able to complete the assignment that's due tomorrow.
As you get closer to the thermite setup (with your safety goggles on, of course!), you realize that the glycerin which will initiate the reaction is about to drip from a locked box. The only way you can stop the reaction is to unlock the box and remove the glycerin.