Doc: All right. Tomorrow night, Sunday, we'll load the DeLorean on to the tracks here on the spur right by the old abandoned silver mine. The switch track is where the spur runs off the main line 3 miles into Clayton...(correcting himself) Shonash Ravine. The train leaves the station at 8:00 Monday morning. We'll stop it here, uncouple the cars from the tender, throw the switch-track, and hijack - (he smirks here as he "corrects" himself again) borrow the locomotive and use it to push the time machine. According to my calculations we'll hit 88 miles per hour just before we hit the edge of the ravine, at which point we'll instantaneously arrive in 1985 and coast safely across the completed bridge.
Marty spots a sign near the model windmill. It says "Point Of No Return."
Marty: What does this mean? "Point of no return"?
Doc: That's: our failsafe point. Up until that point we can stop the locomotive before it plunges over the ravine. But once we pass that windmill, it's the future or bust.
A few minutes later, Doc is sorting out the electricity to work the model.
Doc: Here you go, Marty. Connect that to the positive terminal. All right, Marty, you all set?
Marty: Yeah, yeah, go.
During the following, Doc says his lines as if he is singing them slightly. He also pushes the switch down more to get the train's speed up.
Doc: Train pulling out of the station! Coming up the switch track! Stop at switch track! Throw switch! Pull up the DeLorean! Pushing the DeLorean up to 88 miles per hour!
Both model DeLorean and train fall off the table once they hit the "ravine". The car is caught by Doc, the train lands onto a pillow placed underneath.
Doc: It couldn't be simpler!
There's a knock on the door.
Clara: (o.s) Hello? Emmett?
Doc sees it is Clara.
Doc: It's Clara! Quick, cover the DeLorean.
Marty and Doc cover it with a sheet, and as Clara lets herself in, Marty hides the model DeLorean.
Clara: Hello.
Doc: Why, hello. This is quite a surprise.
Clara: Well, I hope I'm not disturbing anything.
Doc: Oh no, we were just doing a little model railroad.
Clara: Emmett, when my bags were thrown from the wagon, my telescope was damaged. And...since you expressed an interest in science, I thought you might be able to repair it for me. (pause) I would pay you, of course.
Doc: Oh, no, no, no, I wouldn't think of charging you for this.
Marty sighs and runs his hand through his hair.
Doc: (continued) Well, let's have a look at it.
He opens the case and takes the telescope out. He puts it to his eye and closes his other one.
Clara: I think the lens may be out of alignment, because if you move it this way, the image turns fuzzy, see?
She moves closer to Doc and turns the telescope slightly.
Clara: (continued) But if you turn it ... the other way...
Doc takes the telescope from his eyes and lowers his hand. He turns to face Clara and they gaze at each other.
Doc: ...everything becomes - clear.
We get the feeling they will kiss if left alone much longer. Marty does too, so he coughs loudly and causes Doc and Clara to look away from each other quickly. She moves towards the door and Doc hold the telescope with a goofy look on his face. He's definitely in love.
Doc: I will repair it right away and have it for you tonight.
Clara: Oh, tonight's the town festival. I wouldn't dream of having you work on my telescope during such an important event. You are panning on attending, aren't you?
Marty: Well, actually ma'am...
Doc: Of course, the festival...
Clara: Well, in that case, I'll see you this evening at the festival, Emmett.
She turns to Marty as she leaves.
Clara: Mr Eastwood.
Marty: Ma'am.
Clara turns back to look at Doc.
Clara: Thank you for taking care of my telescope.
Doc: You're quite welcome.
Clara leaves and we see that Doc has the most goofiest look on his face we've ever seen him with. Marty goes up to him.
Marty: It's a nice telescope.
That evening. It's the festival, and everyone in Hill Valley has arrived for it. Mayor Hubert stands in front of the clock that will eventually be in the Courthouse.
Mayor Hubert: Ladies and gentlemen! As mayor of Hill Valley, it gives me great pleasure to dedicate this clock to the people of Hill County. May it stand for all time! Tell me when, gentlemen!
Townspeople: 3...2...1...now!
The Mayor starts the clock and fireworks are released into the sky.
Mayor Hubert: Let the festivities begin!