I cautioned you about disrupting the continuum, for your own personal benefit. Therefore, I must do no less.
5 seconds sound clip from the Back to the Future Part III movie soundboard.
You can hear this line at 01:11:26.082 in the DVD version of the movie.
Quote context
[...]
- I've at least got to tell her goodbye.
- Doc, listen. Maybe we I don't know, maybe we can just take Clara with us.
- As you reminded me, Marty, I'm a scientist, so I must be scientific about this.
- We shall proceed as planned, and as soon as we return to 1985, we'll destroy this infernal machine.
- Traveling through time has become much too painful.
[...]