It's a natural thing for Dr. Kemp to seek protection.
3 seconds sound clip from the The Invisible Man (1933) movie soundboard.
You can hear this line at 00:58:51.412 in the Blu-ray version of the movie.
Quote context
[...]
- Now listen carefully. We've got a chance tonight that will never come again.
- He's threatened to murder Dr. Kemp at 10:00.
- And from what we know of him, he'll do his utmost to carry that out.
- He's certain to be near this house, watching for some time beforehand.
- It's a natural thing for Dr. Kemp to seek protection.
- Now, the Invisible Man is certain to be near. He's certain to see what's happening.
- You mean you're going to use me as a bait?
- Yes.
- I can't.
- You must. You'll be perfectly safe.
- I tell you, he's not human. He can go through anything. Prison walls, everything.
[...]