Check fire. There's an officer in the building. I say again, there's a plain-clothes officer in the building!

9 seconds sound clip from the Last Action Hero movie soundboard.

You can hear this line at 00:03:11 in the Blu-ray version of the movie.

Quote context

[...]

- When the governor gets here, call me.

- Slater's attempting to enter. Do not let him in. Repeat, do not let him in.

- Piece of cake.

- Hey. You want to be a farmer? Here's a couple of acres.

- Dekker, the next one I'll hurt.

- Check fire. There's an officer in the building. I say again, there's a plain-clothes officer in the building!

- Jack, what kept you?

- Dad!

- Andy here's been getting nervous. I promised him you'd come. Gave him my word of honor he could watch you die.

- Lose the cannon.

- Has he hurt you, Andrew?

[...]