I would never have believed that this could happen, not through this son of mine.

5 seconds sound clip from the Helen of Troy (1956) movie soundboard.

You can hear this line at 00:56:32.767 in the Blu-ray version of the movie.

Quote context

[...]

- Wait. You were going to say?

- I am Helen, Queen of Sparta.

- The wife of King Menelaus?

- His wife no more.

- The goddess of beauty, Aphrodite, come down to Earth in mortal form. She will bring the disaster I have prophesied. Her name will be written in letters of fire. Helen. Helen of Troy.

- And she saved my life again, but at such risk to herself that I couldn't leave her to the mercy of the Spartans.

- I can see I've troubled you, sire. But in your affection for me and mine for you, I hope you will judge me fairly.

- I would never have believed that this could happen, not through this son of mine.

- This son who shared my hope of everlasting peace. Who promised that he would bring it to us. And what have you brought? Dishonor.

- You have united the Greeks. You have kindled a flame that will weld them together against us. This will bring them to our very shores.

- That should delight you.

- You may have to answer for the death of many a good Trojan.

[...]