You damn fool! Never, never leave this book laying around. Don't you have a safe? No, you don't have a safe. Get a safe. Keep it locked up. And until then, keep it on you like this.
14 seconds sound clip from the Back to the Future Part II movie soundboard.
You can hear this line at 01:09:59.663 in the Blu-ray version of the movie.
Quote context
[...]
- What are you, deaf, old man? He just said it was over. You lost.
- All right, pops. What's the gag? How did you know what the score was gonna be?
- I told you. It's in this book.
- All you gotta do is bet on the winner, and you'll never lose.
- All right. I'll take a look at it.
- And don't tell anybody about it, either.
- Oh, and there's one more thing.
[...]