故事发生在1937年西班牙内战时期，在纷飞的战火之中，一位来自美国的名叫罗伯特（加里·库柏GaryCooper饰）的男人，他的身影时常活跃在前线，带领着西班牙人民抗击当地法西斯的残暴统治。他们炸火车打巷战，打得敌人节节败退。

No man is an island,

Entire of itself.

Each is a piece of the continent,

A part of the main.

If a clod be washed away by the sea,

Motherland is the less.

As well as if a promontory were.

As well as if a manner of thine own

Or of thine friend's were.

Each man's death diminishes me,

For I am involved in mankind.

Therefore, send not to know

For whom the bell tolls,

It tolls for thee.