Oh, rats.
4 seconds sound clip from the Indiana Jones and the Last Crusade movie soundboard.
You can hear this line at 00:32:49 in the Blu-ray version of the movie.
Quote context
[...]
- That's right. If there's a knight of the First Crusade down here, that's where we'll find him.
- It's petroleum. I should sink a well down here and retire.
- Look, it... it must be one of these.
- Look at the artistry of these carvings, and the scrollwork.
[...]