Those men are acting quickly. You don't know how clever their chief is. Clever, and ruthless.
9 seconds sound clip from the The 39 Steps (1937) classic radio play.
You can hear this line at 00:10:05 in the radio play.
Quote context
[...]
- I'm going to tell you something that's not very healthy to know.
- But now that they've followed me here, you're in it as much as I am.
- Have you ever heard of... the Thirty-Nine Steps?
- Thirty-Nine Steps? No. What are they?
- Those men are acting quickly. You don't know how clever their chief is. Clever, and ruthless.
- Come on now, you're trembling.
- Well, you needn't be. You're safe here, you know.
- What you need is a good night's rest.
- You can have my bedroom. I'll sleep on the couch here in the living room.
[...]