We mustn't do anything about it, Tom. Believe me, I know what I'm talking about.
6 seconds sound clip from the The Day the Earth Stood Still (1954) classic radio play.
You can hear this line at 00:42:49 in the radio play.
Quote context
[...]
- All right, Tom... it's true.
- You've just got to promise me you won't say a word to anybody.
- Oh, nobody but the Pentagon.
- Are you crazy? After what happened today? He's a menace!
- You don't understand. You don't realize how important this is.
- Important? Of course it's important. And we can do something about it.
- We mustn't do anything about it, Tom. Believe me, I know what I'm talking about.
- I say he is dangerous. It is our duty to turn him in.
- He isn't dangerous! He isn't a menace! He told me what he came here for.
- Oh, honey, don't be silly because you happen to like the guy.
[...]