- Why don't you go up and surprise him now?
- I will.

6 seconds sound clip from the The Curse of Frankenstein movie soundboard.

You can hear this line at 01:09:40.592 in the Blu-ray version of the movie.

Quote context

[...]

- Paul! Paul, how marvelous to see you! We thought you weren't coming.

- Why, you look wonderful.

- And Victor?

- Oh, he's in his laboratory. He's been almost living there for the past few weeks.

- Oh, what's he doing?

- Oh, as if I should know.

- I don't think I shall ever know what goes on behind that locked laboratory door.

- Of course, I forgot.

- But he'd be awfully pleased to see you, because he was saying only yesterday that he wished you were here because he's got something he wants you to see.

- Has he?

- Why don't you go up and surprise him now?

- I will.

- Who's there?

- Paul.

- Paul? Paul...

- Still keeping the door locked. Is that necessary?

- You can judge for yourself in a moment.

- Elizabeth said you had something to show me.

- Yes. Yes, I have. I've started on brain surgery.

[...]