The Szalinski family is back, this time hilarious disaster strikes when an experiment causes their new toddler son to grow many stories tall.

Diane: There's one thing every little kid knows. Daddies mean fun; mommies mean business.
Diane: I don't understand any of this.
Wayne: Around every electrical operating device, there's a flux. Like an electromagnetic force field.
Clifford Sterling: That's what's causing the baby to grow.
Marshall Brooks: Would this electromagnetic... would it surround neon lights too?
Wayne: Yeah, why?
Marshall Brooks: Your kid. He's heading toward Las Vegas.
Diane, Wayne, Clifford Sterling: Uh-oh.
Wayne: Oh no. Honey, I shrunk the kids.
[Diane has grown to giant size and catches Charles Hendrickson in a helicopter menacing Adam with a tranquilizer gun]
Diane: [to Charles] BACK OFF!
Wayne: You think I'm just some guy from Fresno who tinkered with crack pot ideas in his attic? Well let me tell you something, this country was built on the shoulders of people who tinkered with crack pot ideas in their attics, basements and backyards. Alexander Graham Bell worked in a two room flat!
Clifford Sterling: Young man, don't presume to stand there and lecture me about great minds and great inventors. In all my years I've never worked with anyone who is a fool and I don't intend to start now. So, Charles, you're fired.
Dr. Charles Hendrickson: What?
Clifford Sterling: You're fired! So, Szalinski, what is your plan to get your kid back to normal by bed time?
Nick: Dad, were you ever popular in school?
Wayne: You bet. I was president of the astronomy club three years in a row. We were happenin' guys.
Wayne: Mr. Sterling, sir, I can return my son back to normal!
Clifford Sterling: You can?
Dr. Charles Hendrickson: With what, Szalinski? Coca Cola bottles? Perhaps some chewing gum and twine?
Diane: Just who do you think you are talking to him like that?
Wayne: Diane, let me handle this. Who do you think you are talking to me like that?
Nick: Adam! Don't eat us!
[repeated line]
Adam Szalinski: Toy car...
Mandy: [seeing how large Adam has gotten] There is no way I'm changing those diapers.
[after Wayne finds Nick and Mandy in the shrunken car]
Wayne: Found them. I think we'd better give them a while though.
Adam: I fix it!
Diane: Don't fix it, Adam, just put down Mommy's coffee table.
Diane: Why are you closing the shutters?
Wayne: So one of the neighbors doesn't look in, see a 7 foot baby, and call the National Enquirer.
Adam Szalinski: [hears the doorbell ringing] Doorbell!
Diane: Who's that?
Wayne: One of the neighbors.
Diane: [sarcastically] So far your plan has been working perfectly.
Wayne: I blew up the baby!
[Diane faints]
Adam: Mama fall down! Mama!
Nick: [appears from behind Adam] How'd she take it?
Wayne: About like usual.
Adam: Mama sleeping?
Diane: Just who do you think you are talking to him like that?
Wayne: Diane, let me handle this. Who do you think you are talking to me like that?
Wayne: We're his parents, we'll handle this. Diane, how do we handle this?
Nick: This is your last warning.
[Adam chucks a lamp at him]
Nick: Okay, I'll give you one more warning.
Marshall Brooks: [he is driving an ice cream truck with an ice cream bar on the hood] The next thing I knew, he grabbed it right off the truck.
Captain Ed Myerson: What did he do with it?
Marshall Brooks: What do you think he did with it?
[the ice cream bar, made of metal, has a bite taken out of it and is short-circuited]
Marshall Brooks: [Adam is back to normal size; Brooks gives him an ice cream bar and smiles] Hey, big fella. Is this what you were looking for?