Zadig, a good-hearted, handsome young man from Babylonia, is in love with Sémire and they are to marry. Sémire, however, has another suitor: Orcan wants her for himself. Zadig tries to defend his love from Orcan's threat, but his eye is injured in the process. Sémire abhors this injury, causing her to depart with his enemy. Shortly after, Zadig makes a full recovery and falls into the arms of another woman, Azora, with whom he is married, but who promptly betrays him.