- But we're not going to let that scare us.
- We're not?
- No, Shaggy. We're going to solve this mystery.

6 seconds sound clip from Scooby-Doo, Where Are You! - What the Hex Going On (S1E6).

You can hear this line at 00:09:38.186 in the Blu-ray version of the episode.

Quote context

[...]

- It sure would help if we could find another clue.

- Uh-huh. I found one.

- Groovy! What is it?

- Him.

- It's the ghost!

- Ghost?

- This is the last warning.

- Either the fortune is here by morning or all those in the Wetherby house shall grow old! Now go!

- Wowee! Old horrible really said a frightful mouthful.

- But we're not going to let that scare us.

- We're not?

- No, Shaggy. We're going to solve this mystery.

- Hey, where's Scooby? Uh-oh. I bet he's in that closet. Out to lunch.

- Can you imagine?

- Yeah. With Scooby, I wouldn't be surprised.

- How do you like that? He didn't even invite me.

- Hey, that was the ghost.

- Yeah. He went into the mausoleum.

[...]