Now that you've seen the destructive force of the Reducer Ray, I'll tell you why we asked you to come here. We want you to guard it.
7 seconds sound clip from Superman (1948) - The Reducer Ray (Chapter 3).
You can hear this line at 00:10:53.663 in the Blu-ray version of the episode.
Quote context
[...]
- I'll bet that engineer will never figure out what stopped his train.
- Now we're ready for the Reducer Ray.
- The beam isn't carrying. Something's blocking it.
- Crandall calling Spider Lady.
- You can understand the danger which would threaten the world if it fell into the wrong hands.
- I appreciate your confidence in me. All I can say is I accept the trust and its responsibilities.
- Our New Mexico men were wiped out.
- The Reducer Ray is the greatest force the world has ever known. I intend to capture it.
- If he interferes, I'll find a way to destroy him.
[...]