She smiled at a sorrowful stranger. The smile seemed to make him feel better. He remembered past kindness of a friend and wrote him a thank-you letter. The friend was so pleased with the thank-you letter and he left a large tip after lunch. The waitress, surprised by the size of the tip, bet the whole thing on a hunch.
The next day she picked up her winnings, gave part to a man on the street. The man on the street was grateful, for two days he had had nothing to eat. After he finished his dinner he left for his small dingy room, he didn't know at that moment, that he might be facing his doom. He picked up a shivering puppy and took him to get warm. The puppy was very grateful to be out of the storm.
That night, the house caught fire. The puppy barked alarm. He barked till he woke the whole household and saved everybody from harm. One of the boys he had rescued grew up to be president. All these were because of a simple smile. That smile doesn't cost her a cent.
她朝一个忧郁的陌生人莞尔一笑。这微笑似乎令他感觉好了许多。他记起了曾经帮助过他的一个朋友，于是写了一封感谢信。朋友读完这封信非常高兴，于是用完午餐后留下一份面值不菲的小费。小费面额之大令服务员大为吃惊，凭着直觉，她将小费作为赌注赌了一把。
第二天，她将赢钱悉数清拢，将一部分分给了街头一个乞丐。乞丐万分感激，因为他整整两天粒米未进了。他吃完一顿大餐后回到那间脏兮兮的小屋。他当时并不知道可能要面临厄运。他拾回一只冻得发抖的小狗，为它取暖。小狗免遭天寒地冻，万分感激。
那一夜，房间着火了。小狗吠叫不停以报警，直到将邻里全部唤醒，从而使大家幸免于难。被救的小男孩中有一个长大后成为总统。这一切全都因为一个简单的微笑。而这个微笑却未花分文。