bath...

You had a bathtub, and one day, a bag of noodles fell into the bathtub and disappeared. At first, you didn't understand what was happening, so you threw in a few more bags of noodles. In response, a letter appeared from the bathtub, written with a quill on old paper. The letter contained ancient symbols, and translated, they meant prayers to the gods. The symbols written on the paper were used in the old Qin Yang Empire. Then you realized that whatever you put in the bathtub would end up in theirs. But they didn't know you were doing all this, so they prayed to the gods because they thought the gods were doing it. They also had their own bathtub, and it worked the same way: if they put something in it, it would appear in your bathtub.