Then where are they, and why can't we see them? This is nonsense.

4 seconds sound clip from the Fiend Without a Face (1958) movie soundboard.

You can hear this line at 00:58:55.592 in the Blu-ray version of the movie.

Quote context

[...]

- And then followed these horrible deaths and Gibbons' madness.

- I had to know what I had done. I had to see one of the bodies. I went to the mayor's tomb.

- I now know that I have created a mental vampire, a fiend that needs to drain the intellect to survive and multiply.

(Knocking At Door) I'll get it.

- Supposing you're right, Professor, how does it live?

- How else but on the brains and nerve centers removed from these dead people.

- Then where are they, and why can't we see them? This is nonsense.

- We're facing a new form of life that nobody understands. I believe it feeds on the radiation from your atomic plant, and that it's evil.

- Professor, it's my opinion that the evil's all in your mind. You're in need of medical assistance.

- Doctor, I'm glad to see you're here. This man's become a raving lunatic.

- Hey, what's going on out there? Hey, look!

[...]