A boy obsessed with 50s Sci-Fi movies about aliens has a recurring dream about a blueprint of some kind, which he draws to his inventor friend. With the help of a third kid, they follow it and build themselves a spaceship. Now what?

Ben Crandall: [to Steve Jackson, a school bully] Elephantitis is when something gets bloated and ugly like your ASS.
Ben Crandall: Mom.
Mrs. Crandall: Yeah.
Ben Crandall: Remember that stuff you were tellin' me about your dreams and doin' what you want to do. Well, if I really want to be an astronaut and go out in space - and really do that, it'd be ok, right?
Mrs. Crandall: Sure honey, if that's what you really want to do.
Ben Crandall: Ok.
Mrs. Crandall: [hugs him] Sleep tight.
Ben Crandall: Good night.
[then, after she's left the room]
Ben Crandall: Bye Mom.
Starkiller: Bloodshed is my life.
Ben Crandall: What's that?
Wak: Uhh... Space Pirates.
Mr. Müller: [to his son's "talking" rat] "Shut up, Heinlein!"
Ben Crandall: [stuttering, astounded at the violent film footage] But thi - see, this isn't real! A-a-and we don't really kill people! Well, we do, b-but n-not aliens, 'cause we haven't met any!
Ben Crandall: I've waited all my life to say this.
Darren Woods: Be my guest.
Ben Crandall: We come in peace.
Wak: Its a brand new car!
Wak: The Rolls Canardly... Rolls down one hill CanArdly get up the next!
Wak: Way to go, stupid!
Ben Crandall: He's about to say something.
Wak: [in Bugs Bunny's voice] Ehhhhhhhhhhh, what's up doc?
Ben Crandall: [long pause] What?
Heinlein the Mouse: [pressing buttons] I would like... cheese... go... to... hell...
Darren Woods: [about "beings" on other planets] Maybe it's a bunch of Amazon rainforest women that wanna breed a new race.
Wolfgang Müller: You pervert.
[watching the movie "Starkiller"]
Wolfgang Müller: Explosions in space? It's impossible.
Ben Crandall: What do you mean? You can hardly see the strings.
Wak: Look, I know I must look weird to you but how do you think you look to me? Listen, I watched four episodes of "Lassie" before I figured out why the little hairy kid never spoke. I mean, he rolled over, sure, he did that fine but, I don't think he deserved a series for that.
Darren Woods: She was a good ship.
[last lines in the film]
Ben Crandall: If this is all a dream, what's gonna happen when we wake up?
Wolfgang Müller: I don't know, but I can't wait to find out.