Edna: Look what we have here. A miserable failure.
Marty: Edna! What are you doing here?
Edna: Watching poor Emmett fail his science experiment.
Emmett: Watch it!
Edna: You are a failure and the only way you can succeed is to have me guide you!
Emmett: I'm done with you Edna! I don't want to see you again!
Sylvia: And the winner of the Hill Valley Expo goes to Emmett Brown!
(Audience cheers and applauses)
Marty: Congratulations Emmett! (goes up to the stage to receive the award)
Edna: Grrrrrr….
Marty: Calm down Edna. Once you go to jail, you'll finally get over you and Emmett's breakup.
Edna: Hey get your…aahhhh
Danny Sr.: Caught you this time!
Edna: No way I'm going to jail (runs out the door)
Danny Sr.: Hey! You get back here this instant! (runs for her)
(Edna hides in back of the High School and witnesses the DeLorean time machine)
Doc: Edna?
Edna: Mr. Sagan. Good to see you again. What's this machine thing?
Doc: Get out of there! It's very dangerous and you'll get killed!
Edna: Oh please I can't get killed in this time machine!
Marty: Get out now or I'll have Officer Parker come here to get you!
(Edna punches Marty then Doc and drives away in the DeLorean)
Doc: No! Edna! (Him and Marty run for the driving DeLorean)
(Edna drives very fast crashing a tent and sonic booms go off traveling to 1883)
Marty: Damn it we missed her. What are we going to do?
Doc then starts to fade out as his Citizen Brown self ceases to exist.
Marty: Doc! No!
Doc: Marty. Please go on without me.
Marty: But Doc...
Doc: Marty. We've already succeeded in our mission to break up my younger self and Edna. (Fades from existence)
Marty: Doc! Oh no, what am i gonna do? (Sees the western union truck and guy; gets an idea)
He writes a letter to Doc that states,
Dear Doc,
I am writing you this letter to inform you that I am currently stuck in October 10, 1936. I came here with another you from an alternate universe to stop you and Edna Strickland from being together. Edna just stole the DeLorean and went either to the past or the future (hopefully). Please make another type of DeLorean so you can come back here to take me back to May 18, 1986. You will find out how this whole Edna controlled timeline happened after 1985.
Your friend,
Marty McFly
Western Union man: Um hold this for 49 years?
Marty: Here's some money to keep it for that long. Does that suffice?
Western Union: Yeah I suppose.
He then gives it to the Western Union man with money to hold it until October 18, 1985 but will say not to open it until May 17, 1986. The DeLorean and the train then appears away with sonic booms. He runs over to check.
Marty: Doc?
Doc: Marty!
Marty: Thank God it worked. And why did you bring Clara and the boys here?
Clara: To make sure you were alright of course.
Marty: Yeah I'm fine but we don't know if Edna went into the past or the future.
Verne: Hopefully the future. I mean the far distant future.
Jules: Wow! A science fair!
(Hill Valley Telegraph truck parks in front of them and Marty's great grandfather William McFly hops out. He looks like the 2015 version of Marty from Part 2)
William: Do you guys know where my son Artie is?
Marty: Artie McFly?
William: Yes I came to meet his soon to be wife Sylvie.
Marty: They're in the gym.
William: Thanks. (Walks into the gym)
Clara: Marty was that…
Marty: Yes that was my great grandpa Willie. I met him in 1885 when he was a baby.