At that moment Ambrosio's courage failed him.

Might not Matilda have deceived him?
Might not Jealousy have persuaded her to destroy her Rival, and substitute poison in the room of an opiate?
This idea appeared so reasonable that He was on the point of preventing her from swallowing the medicine.

His resolution was adopted too late: The Cup was already emptied, and Antonia restored it into Flora's hands.

No remedy was now to be found: Ambrosio could only expect the moment impatiently, destined to decide upon Antonia's life or death, upon his own happiness or despair.
Dreading to create suspicion by his stay, or betray himself by his mind's agitation, He took leave of his Victim, and withdrew from the room.

Antonia parted from him with less cordiality than on the former night.