Ominous, most ominous.

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

You can hear this line at 00:02:43.485 in the Blu-ray version of the TV Series episode.

Quote context

[...]

- Oh! How can I ever, ever thank you?

- What? The Penguin prevented a crime? That waddling pompous master of foul play?

- It's true, commissioner.

- And who do you think, the necklace belongs to? Ms. Sophia Starr.

- Sophia Starr? Beauteous queen of Gotham City society?

- That's her.

- They left the theatre hand in hand.

- Ominous, most ominous.

- What do you think it means, commissioner?

- Since it involves The Penguin, there is only one man who can answer that question. And answer it in time. The Caped Crusader.

- Alright, commissioner, I'll fetch him for you.

- And in Wayne Manor, where young Dick Grayson practices his putting under the watchful eye of his guardian millionaire Bruce Wayne and his doting Aunt Harriet.

[...]