It is as if he has been given the negative and positive ends of a battery.

He believes that his mother is here, in this city.

Can that have anything to do with his father's coming?
A feeling of resentment springs up, then dies away as he gets a good look at his parent's face.
"Father, what has happened?
Have you failed; has any disaster come upon us ?" "Why do you ask that, John ?" "Your face; it is changed so.

I miss something I have been accustomed to see there." Duncan Craig smiles.
"Ah! John, my boy, please Heaven, I am changed.

I have been humbled in the dust, and I believe I have emerged from the furnace, I trust, a far better man." John is puzzled.