- How did you know we were in here?
- We didn't. We were on the other side of the island.

4 seconds sound clip from the Attack of the Crab Monsters (1957) movie soundboard.

You can hear this line at 00:31:58.149 in the DVD version of the movie.

Quote context

[...]

- I don't understand this. We've covered every exit in the base of the pit. Wounded as he was, he couldn't have crawled this far.

- Yet, still no sign of him.

- Nor will be, eh, Karl?

- Get close to the walls!

- Something to tie it with.

- Top of my pack, Karl.

- Here, you'll need a tourniquet too.

- Hello there, anybody alive?

- He all right?

- How did you know we were in here?

- We didn't. We were on the other side of the island.

- Well, what used to be the other side of the island. Most of it's fallen to the drink already.

- So we run in here when we heard you call.

- Call? We didn't call you.

- Whose voice did you hear?

- Well, it sounded like the other guy. You know, the fellow who fell into the pit.

- So he is still alive.

- If we do not move fast, Jules will not be alive. Come, give us a hand.

[...]