- 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.

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

You can hear this line at 00:18:24.691 in the Blu-ray version of the movie.

Quote context

[...]

- Anger won't keep the boy from doing it again. We must tell him why.

- You know the terrible things that have happened when Ro-Man landed on earth. The only reason we are still alive is that your sister Alice and I worked out a way to reflect his deadly beams away from the house.

- He can't see us, he can't hear us, but one word spoken outside the barrier and he will be down on us. Do you understand that, Johnny?

- But I saw him!

- Saw who?

- Ro-Man. He's in the cave at the end of the ravine.

- Then he's found us out.

- Not yet, or we'd all be dead by now. Are you sure?

- 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?

[...]