For Whom the Bell Tolls

That is a tricky book including complex scenarios and odd words... 

Here are three facts:

1. The story was took place at the back-line(back of the front) of the war in Spain.

2. The main characters in the 1st chapter are Anselmo(an old man), Robert Jordan(a young man) and Pablo(was a guerrilla). And I think Anselmo and Pablo were Spanish, because it was mentioned somewhere in the 1st chapter indirectly.

3. Robert Jordan was sent to bombard the bridge through
which the enemies bring the reinforcement.