His melancholic nature easily fell to brooding over any evil which was strong enough to break the barrier of his indifference; and the annoyances which had sprung originally from so small a cause had grown to gigantic proportions, and had struck at the very roots of his happiness.
He had begun by disliking Del Ferice in an indifferent way whenever he chanced to cross his path.

Del Ferice had resented this haughty indifference as a personal insult, and had set about injuring Giovanni, attempting to thwart him whenever he could.

Giovanni had caught Del Ferice in a dastardly trick, and had been so far roused as to take summary vengeance upon him in the duel which tools place after the Frangipani ball.

The wound had entered into Ugo's soul, and his hatred had grown the faster that he found no opportunity of revenge.

Then, at last, when Giovanni's happiness had seemed complete, his enemy had put forward his pretended proof of a former marriage; knowing well enough that his weapons were not invincible--were indeed very weak--but unable to resist any longer the desire for vengeance.