There's a door up ahead!
1 seconds sound clip from Scooby-Doo, Where Are You! - The Backstage Rag (S1E9).
You can hear this line at 00:18:04.606 in the Blu-ray version of the episode.
Quote context
[...]
- Look at that printing press.
- And all those new $20 bills on the table.
- You were right, Freddy. It's a big counterfeit operation.
- Yipes!
- Double yipes! Let's get out of here!
- Golly! Where's that voice coming from?
- This ladder's our only way out, but it's too dark to see where it goes.
- We got no choice. Start climbing.
- Ha ha ha! You have learned my secret. Now you can never go.
[...]