Then he walked the room for an hour or two, revolving in his mind what he should say to Mercy.

His ideas arranged themselves concisely and clearly.

He had been stung by Mercy's letter into a frame of feeling hardly less inexorable than her own.

He said to himself, "She never truly loved me, or nothing under heaven could make her believe me capable of a dishonesty;" and, in midst of all his pain at this thought, he had an indignant resentment, as if Mercy herself had been in some way actively responsible for all this misery.
His letter was shorter than Mercy's.

They were sad, strange letters to have passed between lovers.