But The Riddler's smart and tricky. If he suspects a trap, he'll pass up the cash and destroy the monument.

11 seconds sound clip from Batman (1966) - When the Rat's Away the Mice Will Play (S1E12) TV Series.

You can hear this line at 00:15:20 in the Blu-ray version of the movie.

Quote context

[...]

- Am I free to speak?

- I trust Bruce Wayne as I trust you, Batman.

- Good. I have a plan. I suggest no cops. Police, that is.

- 9 o'clock, have your men place the money inside the museum, in the torch room with the monument. Then they must leave.

- Million dollars is a lot of money.

- But The Riddler's smart and tricky. If he suspects a trap, he'll pass up the cash and destroy the monument.

- Then how do we catch him?

- You leave that to Robin and me.

- You have to deactivate the bomb wherever it is before he leaves. Then we will jump into action.

- I know nothing whatsoever' about this sort of thing, commissioner, but as a layman, it makes sense to me.

[...]