I can't, Clara. I wish it didn't have to be this way, but just believe me when I tell you that I'll never forget you and that I love you.
10 seconds sound clip from the Back to the Future Part III movie soundboard.
You can hear this line at 01:13:07.016 in the DVD version of the movie.
Quote context
[...]
- Goodbye? Well, where are you going?
- I'm going away. And well, I'm afraid I'll never see you again.
- Emmett!
- Clara, I want you to know that I care about you deeply.
- But I've realized that I don't belong here, and I have to go back where I came from.
- Well, wherever you're going, take me with you.
- I don't understand what you're trying to say.
- Clara, I don't think there's any way that you can understand it.
- Please, Emmett. Please, I have to know. If you sincerely do love me, then tell me the truth.
[...]