— Doc! Doc, come in!
— Marty, come in.
— Listen, Biff's guys chased me into the gym and they're gonna jump... me.
— Then get out of there!
— No, Doc, not me. The other me. The one that's up on stage playing «Johnny B. Goode».
— Great Scott! Your other self will miss the lightning bolt. You won't get back to the future and we'll have a major paradox!
— Wait. A paradox? You mean one of those things that can destroy the universe?
— Precisely.
01:24:39