Hey, gang. There's a maze of secret passages down there.
4 seconds sound clip from Scooby-Doo, Where Are You! - Mine Your Own Business (S1E4).
You can hear this line at 00:16:47.608 in the Blu-ray version of the episode.
Quote context
[...]
- Phew. We finally got away from that gooney miner.
- Uh!
- Groovy.
- Hey, what happened to Daphne?
- Wouldn't you know it? Danger-prone Daphne fell into a mine shaft.
- Uh-huh.
- Hey, gang. There's a maze of secret passages down there.
- And guess what I saw in that mine.
- I guess Hank wasn't kidding about that ancient miner.
- Do you suppose that's the miner moaning?
- Well, like, if I had a face like that, I'd moan, too.
[...]
