The Evil That Men Do

I think it's about Romeo & Juliet.

'slept in the dust with his daughter' 'Him' sounds suspiciously like Lord Capulet

'Her eyes red with the slaughter of innocence' Juliet has to suffer because of the slaughter of innocence, the killing of Mercutio

'But I will pray for you And some day I may return Don't you cry for me Beyond is where I learn'

All that is after he is banished from Verona.

And the dust part might refer to the fact that their engagement was secret.

Awesome song.