Complete the objective “Did you call the plumber?” in the “Plumbing against one's will” quest.
You’ll have to cover all the pipes in the right order. Start by getting rid of all the puddles except for the one marked in red (see the picture). This puddle is controlled by pipe #3.Then go to pipe #2, click on it, and go back to the previous room through the glass doors. Then click on pipe #3 again.Then click on pipe #1.Then go back to pipe #3. The path is now clear, so you can reach the last pipe and complete the objective.