Marty: Ronald Reagan.
Doc: Ronald Reagan, the actor? Then who's Vice President? Jerry Lewis?
During the following Doc leaves his house and goes to his garage with some things. Marty follows him.
Doc: I suppose Jane Wyman is the First Lady.
Marty: Whoa, wait, Doc.
Doc: And Jack Benny is Secretary of the Treasury.
Marty: Look, you gotta listen to me.
Doc: I've had enough practical jokes for one evening. Good night, Future Boy!!
Doc closes the garage door. Marty talks desperately through it to him.
Marty: No wait, Doc, the bruise, the bruise on your head, I know how that happened, you told me the whole story. You were standing on your toilet and you were hanging a clock, and you fell, and you hit your head on the sink, and that's when you came up with the idea for the flux capacitor, which is what makes time travel possible.
Doc opens the door and stares at Marty with amazement. He was telling the truth! Cut to outside the Lyon Estate signs. Doc and Marty are looking at the DeLorean.
Marty: Something wrong with the starter, so I hid it.
Doc: After I fell off my toilet, I drew this.
Doc shows Marty a drawing of the flux capacitor.
Marty: Flux capacitor.
Marty shows Doc the real thing. Doc is amazed.
Doc: It works, ha, ha, ha, ha, it works! I finally invent something that works!
Marty: Bet your ass it works.
Doc: Well, now we gotta sneak this back into my laboratory. We've gotta get you home!
Back at the lab, Marty is plugging the video camera into Doc's TV.
Marty: OK Doc, this is it.
The video starts playing. 1985 DOC starts speaking on the video.
1985 Doc: (on video) Never mind that, never mind that now...
Doc: Why that's me! Look at me, I'm an old man!
1985 Doc: (on video) Good evening, I'm Dr Emmett Brown, I'm standing here on the parking lot of Twin Pines Mall. It's Saturday morning, October 26th 1985.....
Doc: Thank God I still got my hair. What on Earth is that thing I'm wearing?
Marty: Well, that's a radiation suit.
He starts fast-forwarding the video.
Doc: Radiation suit, of course, 'cause of all of the fall out from the atomic wars. This is truly amazing, a portable television studio. No wonder your President has to be an actor, he's gotta look good on television.
Marty: Whoa, this is it, this is the part coming up, Doc.
1985 Doc: (on video) No, no, no, this sucker's electrical, but I need a nuclear reaction to generate the 1.21 gigawatts of electricity...
Doc: What did I just say?
Marty rewinds the tape.
1985 Doc: (on video) No, no, no, this sucker's electrical, but I need a nuclear reaction to generate the 1.21 gigawatts of electricity that I need.
Doc: 1.21 gigawatts? 1.21 gigawatts! Great Scott!
Marty: What the hell is a gigawatt?
Doc runs over to his portraits.
Doc: How could I have been so careless? 1.21 gigawatts! Tom (re: Thomas Edison), how am I gonna generate that kind of power? It can't be done, it can't!
Marty: Doc, look, all we need is a little plutonium!
Doc: (sarcastically) I'm sure that in 1985, plutonium is available at every corner drug store, but in 1955, it's a little hard to come by. Marty, I'm sorry, but I'm afraid you're stuck here.
Marty: Whoa, whoa Doc, stuck here, I can't be stuck here, I got a life in 1985! I got a girl!
Doc: Is she pretty?
Marty: Doc, she's beautiful. She's crazy about me.
Marty gets the flyer out of his pocket.
Marty: Look at this, look what she wrote me, Doc. That says it all. Doc, you're my only hope.
Doc: Marty, I'm sorry, but the only power source capable of generating 1.21 gigawatts of electricity is a bolt of lightning.
Marty realises something!
Marty: What did you say?
Doc: A bolt of lightning, unfortunately, you never know when or where it's ever gonna strike.