You know, it could still be you that gets shot tomorrow. This tombstone could still be in your future.

6 seconds sound clip from the Back to the Future Part III movie soundboard.

You can hear this line at 01:09:28.673 in the DVD version of the movie.

Quote context

[...]

- You've got to do what you've got to do, and I've got to do what I've got to do.

- Marty, I've made a decision. I'm not going with you tomorrow. I'm staying here.

- What are you talking about, Doc?

- There's no point in denying it. I'm in love with Clara.

- Oh, man!

- Doc, we don't belong here. Neither one of us.

- You know, it could still be you that gets shot tomorrow. This tombstone could still be in your future.

- Marty, the future isn't written. It can be changed. You know that. Anyone can make their future whatever they want it to be.

- I can't let this one little photograph determine my entire destiny.

- I have to live my life according to what I believe is right in my heart.

- Doc, you're a scientist. So you tell me what's the right thing to do up here!

[...]