The kryptonite will be the means of acquiring the secret of the relativity reducer ray. With its concentrated force, it can blast any known target in the world.
8 seconds sound clip from Superman (1948) - Superman In Danger (Chapter 6).
You can hear this line at 00:04:01.424 in the Blu-ray version of the episode.
Quote context
[...]
- Stop kidding, I'm not in the mood for fun.
- This kryptonite is supposed to handle him.
- Look, it works. The kryptonite can stop Superman.
- A good job well-done, gentlemen. Thank you.
- With Superman under control... the job should be easier.
- We're dealing with the deadliest and most powerful forces. Kryptonite and the reducer ray.
- What scientist would work with us?
- None. Until we work out a plan to get him out of prison.
- What's that? A prisonbreak? When did it happen? Is he still at large?
[...]