Alfred is going to be our secret undercover agent.

4 seconds sound clip from Batman (1966) - The Penguin Goes Straight (S1E21) sitcom.

You can hear this line at 00:12:37.286 in the Blu-ray version of the TV Series episode.

Quote context

[...]

- We substitute fake jewels with the real ones. Treat it in a reactor to leave radioactive traces of the thief.

- Terrific!

- There's just one problem.

- To make copies. I don't know what the real ones look like.

- Correct.

- He has to look at them. That would tip Penguin off.

- Pickup the Bat-phone and call Alfred. Tell him to wait for us in the Bat-cave.

- Alfred is going to be our secret undercover agent.

- What?

- Reggie Rich gave you a check for $10000 and you tore it up?

- Indeed. And right in front of his very eye.

- You know somethin', this plan of being a straight guy must have unhinged Penguin's mind.

- No, you, butt-brain. What's 10000, when I aim at millions?

- Confidence. That's is what I'm stealing from these dupes. Confidence and pride in The Penguin. And they'll end up handing me their treasure on a silver plate.

[...]