- Cat?
- It's just an expression.

3 seconds sound clip from the The Cat from Outer Space (1978) movie soundboard.

You can hear this line at 00:54:12.825 in the Blu-ray version of the movie.

Quote context

[...]

- I.D. Wilson, Frank. Doctor. Social security, 631070829.1951 to '55. US Navy. '55 to '62, Caltech. Current employment, theoretician. ERL?

- That's my Dr. Wilson!

- The scoundrel!

- We'll have him in the slammer within the hour, sir.

- And blow the whole ball game?

- Gentlemen, we're after Mr. Big, and this double-crossing fink is gonna lead us to him. To find the rat, tail the cat.

- Cat?

- It's just an expression.

- Want a peanut, Jake?

- No, thanks. I'll wait till Frank gets back.

- The Rams still ahead?

- Ahead? Frank, the Rams won the game.

- And without Jake's help. Without your help, buddy.

- Great, let's break open the six-pack.

- What will you have, Jake?

- Did you get some more of that tuna?

- Yeah, yeah. Coming right up.

[...]