休息日，父子俩各自干着感兴趣的事。

On weekends, father and son do the things they are interested in respectively.

儿子用气球放走了他的“航空信”。

Son releases his “air mail” with balloon.

几天后，父子二人欢乐地走在山间的小路上。

A few days later, father and son walk in a mountain path joyfully.

爸爸： “儿子，快看！那是什么飘过来了？”

Father: “Look! Son! What is that drifting in the wind? ”

父亲打开信，怎知竟是儿子的恶作剧。

Father opened the letter, and realized that this is his son's mischief.

结果……儿子受到预料之中的教训。

Eventually…Son is given a lesson expectedly.