This is the first volume of Stories of Smart Children in Ancient China series. One day, Si Maguang was playing hide and seek with his friends in the backyard where there was a big water vat. One of his friends climbed up to the vat but accidentally fell into it. The vat was deep and full of water. The child was drowning. Other children saw this and were all frightened into crying. They ran out to ask adults for help. At that moment, Si Maguang suddenly came up with an idea. He picked up a huge stone and threw it against the vat. The vat was broken and water came out from the hole. The child was thus saved.