If the plunger doesn't work, the next tool to try is a toilet auger (also known as a closet auger). This is a long, flexible rod that can be inserted into the toilet drain to break up or retrieve the blockage.

If all else fails, you can try using a chemical drain cleaner to clear the blockage. However, be careful when using these products, as they can damage your toilet or pipes.

The water was dangerously close to the rim. Remembering a crucial tip from a Step-by-Step Guide , Mark reached behind the toilet and twisted the clockwise to stop the water flow immediately. He then removed the tank lid and pushed the flapper valve down for extra security. Act II: The Chemistry Experiment