That's the boy. I knew you had it in you.
5 seconds sound clip from the After the Thin Man (1936) movie soundboard.
You can hear this line at 00:21:39 in the DVD version of the movie.
Quote context
[...]
- Uh, well, I wouldn't go as far as to say that.
- What's that? Oh, uh, just a moment.
- That's the boy. I knew you had it in you.
- Oh, yes. If you gentlemen will excuse me.
- I don't know when I've spent such a stimulating evening.
- Aunt Katherine wants to speak to you.
[...]