【成语来源】 

a false alarm
杯弓蛇影

In Jin Dynasty there was a man named Yue Guang who was fond of drinking alcohol.
晋朝有个叫乐(yuè)广的人，爱喝酒。

One day, he invited a friend to his house to drink together.
一天，他邀请朋友到家里来对斟对饮。

Suddenly, his friend saw the reflection of a snack swimming in the goblet.
忽然，朋友看见酒杯里有条蛇影在游动。

He got so much frightened that he took ill on bed after getting home.
他受了惊吓，回去便一病不起。

And neither any doctor or any medicine could cure his illness.
请医服药，都无起色。

Yue Guang came to see him and asked about the cause of his disease.
乐广跑来看他，问明起病的缘由。

When he got to know the cause, he pulled his friend from the bed immediately and took him to his house.
乐广听后一把拉起朋友往家走。

Yue Guang made his friend sit where he used to, pouring a goblet of alcohol for him, and asked him," Is there any snake reflection in the goblet?"
他让朋友坐在原处，斟满酒问：“有蛇影吗？”

There was still a "snake reflection" in the goblet! Yue casually took away the bow hanging on the wall.
杯子里还有“蛇影”！乐广随手取下墙上的弓。

This time, the "snake reflection" disappeared.
这次，“蛇影”不见了！

"So it was the bow reflection that was in the goblet!" His friend at once got well from his illness.
“杯子里原来是弓影呀！”朋友的病情顿时好了！

【文化链接】

其实“杯弓蛇影”的意思有点偏向于以前已经讲解过的“草木皆兵”，也有点“虚惊一场”的意思，英语中就可以用“a false alarm”，也就是“一个错误的讯号”的意思。我们来一起通过下面一个小漫画来更加了解这个成语吧~

Subway False Alarm
地铁“杯弓蛇影”事件

On the subway yesterday morning and this guy I saw sleeping at the beginning of the subway (and then forgot about) fell totally on his face and completely on the floor.
昨天早晨在地铁里我看到一个人睡着，然后俯身摔倒在地。

He kind of shook it off and got back into his seat.
结果他震醒了，又回到了自己的座位上。

Though for a moment I was thinking if he was really unconscious who would be the one to check him?
其实我原来还以为他真的已经不省人事了，还在想有谁能帮他检查一下呢……