This secret passage, sir, how convenient for you.

5 seconds sound clip from the The Pit and the Pendulum (1961) movie soundboard.

You can hear this line at 00:43:37 in the Blu-ray version of the movie.

Quote context

[...]

- The meaning, Doctor, is this. Only one person in this castle could have caused all these inexplicable occurrences. That person is Don Medina.

- What? (2)

- You are mad, sir.

- Am I?

- Mr. Barnard, I swear that I...

- This secret passage, sir, how convenient for you.

- Enabling you to whisper to Maria without being seen.

- Then, after the door to Elizabeth's room had been locked by you, enabling you to return there and at your leisure demolish everything.

- You are wrong, sir. I swear, I...

- You are lying, sir!

[...]