Else he might have concluded that if in a moment in which by delivering her from captivity he deserved her gratitude, yet she expressed herself in bitterness, it must be because that bitterness was anterior to the gratitude and deep-seated.

She had been moved to it by hearing of the course he had taken.

Why?
It was what he did not ask himself, or some ray of light might have come to brighten his dark, his utterly evil despondency.
Surely she would never have been so moved had she not cared--had she not felt that in what he did there was a personal wrong to herself.

Surely, he might have reasoned, nothing short of this could have moved her to such a degree of bitterness and scorn as that which she had displayed.
That is how you will reason.

Not so, however, reasoned Captain Blood.
Indeed, that night he reasoned not at all.