- Maybe we could kill him, huh, Pop?
- No, Johnny. The armies of the entire world tried and failed.

— The Professor (John Mylong)

7 seconds sound clip from the Robot Monster (1953) movie soundboard.

You can hear this line at 00:18:42.496 in the Blu-ray version of the movie.

Quote context

[...]

- I was in the cave, painting his picture the way we saw him on the viewer screen.

- Why were you doing that, Johnny?

- So in case he did wipe out the human race, there'd be some record of how it happened.

- Go on, go on!

- I heard him coming, ducked out just in time.

- Looked to me like he was making it his home.

- Why here? Why so close?

- Maybe we could kill him, huh, Pop?

- No, Johnny. The armies of the entire world tried and failed.

- We have thrown everything we had at him, but he's impervious.

- Unless we can find his weak spot.

- Could I have just a little water, Mom?

- Yes, dear.

- But why here? Why here?

- Perhaps we're the last people on earth, Dad. He senses our presence and keeps calculating closer and closer.

[...]