The truth flashed upon him at once.

The fellow had been listening, and had probably heard all.

Giovanni instantly resolved to conceal the fact from the Duchessa, to whom the knowledge that the painful scene had been overheard would be a bitter mortification.
Giovanni could undertake to silence the eavesdropper.
Quick as thought his strong brown hands gripped the throat of Ugo del Ferice, stifling his breath like a collar of iron.
"Dog!" he whispered fiercely in the wretch's ear, "if you breathe, I will kill you now! You will find me in my own house in an hour.

Be silent now!" Giovanni whispered, with such a terrible grip on the fellow's throat that his eyeballs seemed starting from his head.

Then he turned and went out by the way he had entered, leaving Del Ferice writhing with pain and gasping for breath.