Lea Thompson and writer Bob Gale on the 35th anniversary of ‘Back to the Future’

The first “Back to the Future” movie hit the big screen in 1985. It was written by Bob Gale and Robert Zemeckis, who also directed the film. Michael J. Fox played Marty McFly in all three movies, but he wasn’t originally cast in the role. Actor Eric Stoltz got the part, and six weeks into production was replaced by Fox. “You could feel it,” Gale tells Yahoo Entertainment about bringing in Fox. “This kid is great. He really is Marty McFly. The movie is going to work with him in the lead.” Lea Thompson remembers the casting shakeup being “weird.” She recalls getting phone calls from executive producer Steven Spielberg and director Zemeckis about Stoltz being fired. “I was like, ‘Oh my god, they fired me,’” she says. Thompson says working closely with Fox “was really fun.” “I love him to this day,” she adds. “He’s a funny wonderful man.”

Video Transcript

- Next Saturday night, we're sending you back to the future.

- OK, all right, Saturday's good. Saturday's good. I can spend a week 1955. I can hang out. You can show me around.

KEVIN POLOWY: Well Bob, congrats to you, sir, on "Back to the [? Future's" ?] recent 35th anniversary. One of my favorite movies of all time-- and franchises, for that matter. But I wonder, was there a moment or a day on set where you first truly felt like, this is going to be something special. Now, I've got to imagine that would have probably-- if there was that moment, it happened after the casting shakeup.

BOB GALE: That's right. That was a seminal moment for me. Here we had been shooting for six weeks. We kept making excuses-- maybe the movie will be OK if we use this take of Eric, and that take of Eric, and cut it all together. And then having seen that it wasn't working, as soon as Michael J. Fox started doing the scene with Christopher Lloyd about time travel-- oh my god.

Everybody in the company thought we were insane, because you don't replace an actor after this many weeks of shooting. You could just feel it-- oh my god, this kid is great. He really is Marty McFly. The movie is going to work with him in the lead.

LEA THOMPSON: I understand, as a director, what Michael brought that was different than what Eric brought. But it's just-- still, it's weird. It's just scary when it happens. I remember I was in Europe-- and I wasn't supposed to be-- when they fired Eric. And I had that old phone machine, and you would call in, and there were just, like, messages from Spielberg and Zemeckis. And I was like, oh my god, they fired me.

KEVIN POLOWY: It sounds like that was a decision you guys really had to labor over. I can't imagine that was an easy thing to go through, letting an actor go like that.

BOB GALE: Well, it was not an easy thing to do, especially because there were no precedents for it. We had a very great ally in Steven Spielberg, backing us up. And Steven had wisely counseled us when we knew we wanted to replace Eric. He said keep shooting until you get a replacement.

So the first call that we made was to Gary David Goldberg, producer of "Family Ties." They only had about eight more weeks to shoot. And he said, OK, if Michael is up for working this way, in which you guys will adjust your schedule around ours, and you won't even get to work with Michael until 5:30 or 6:00 PM every night, it's OK with me. And Michael said, yeah, yeah, yeah. I'm 22 years old. I don't need to sleep. I'll do it. Sure.

- You made it.

- Yeah.

KEVIN POLOWY: So Michael was filming "Family Ties" through the day, and then coming on to "Back to the Future" towards that evening, and shooting well into the early hours. Yeah, he's 22, but was he ever exhausted?

BOB GALE: He was exhausted all of the time. Are you kidding? Yeah. What would happen is, we'd have a station wagon pick him up at Paramount. This would be around 5:30, 6:00 PM. And they take him out to our set, and we'd work with him until 1 or 2 o'clock in the morning. He'd sleep in the van or the station wagon going home.

LEA THOMPSON: You could tell he was exhausted. We felt really badly for him, but he was a trooper, and he was young. Michael, at that point, is like-- he was in such great comedy shape. He was just so tuned up that he could actually pull this off getting zero sleep. I mean, they had some kind of like station wagon. They'd throw him in back with blankets. It was so sad. Poor guy.

KEVIN POLOWY: How did you guys strike such a perfectly awkward, like, reverse oedipal dynamic?

LEA THOMPSON: Well, that's the fun thing. But the more pressure I put on him, the more freaked out he got. So it was really fun, because he could feel it. So it kind of encouraged me to be more, like, you know, do my cat in heat thing with him. And he just would really respond to it. So that's the fun. That's like playing. And playing with someone at your level. I love him to this day. He's a funny, wonderful man.

KEVIN POLOWY: In one of the most famous scenes, Lorraine keeps calling Marty Calvin.

- That is your name, isn't it? Calvin Klein? It's written all over your underwear.

KEVIN POLOWY: Have you ever met Calvin Klein?

LEA THOMPSON: No, and I think I deserve free merch.

KEVIN POLOWY: Why did Lorraine take Marty's pants off anyway?

LEA THOMPSON: I don't know. You know, originally, I took off his underpants that happened. That happened. But they changed it.

KEVIN POLOWY: The new 4K release features some amazing old audition tapes. You have Ben Stiller and Jon Cryer going out as Marty McFly. Billy Zane going out for Biff. And Kyra Sedgwick as Jennifer Parker. Which of those, over the years, really stuck out in your mind, and made, at the time, really tough calls for you guys.

BOB GALE: My thanks and kudos to all the actors that gave us permission to use those auditions on this. There are a lot who didn't do that. You don't see Johnny Depp, and you don't be John Cusack in these. And they just said no to us when we asked. Jennifer Jason Leigh was a runner up for Lorraine. She came close. We just liked Lea Thompson better.

LEA THOMPSON: I definitely remember C. Thomas Howell, because we had done "Red Dawn" together. So we were definitely really good friends.

- Wolverines!

LEA THOMPSON: My final screen test, which was in Amblin-- the room was really dark, and Steven Spielberg was operating this giant video camera. They just made me feel so welcome. I remember I had to put on a wig to play the old Lorraine, and try to convince him that I could do both parts. And it was a great memory of mine. And usually auditions are horrible. But this one was good.

KEVIN POLOWY: Jennifer Jason Leigh was a close second for Lorraine.

LEA THOMPSON: Oh really? Jennifer Jason Leigh beat me out for about 100 other parts, so I guess that I should have gotten one. And this was the one. This was the one to get.

KEVIN POLOWY: What do you remember about Johnny Depp going out for Marty McFly?

BOB GALE: You know what, I don't remember really a whole lot about the auditions, because we were just so hard-pressed and anxious to find the perfect Marty McFly. And remember, Johnny Depp wasn't Johnny Depp back then. We just saw this guy who was clearly talented, but he wasn't right.

- Hello, anybody home?

KEVIN POLOWY: Well, Biff Tannen has come up a lot these past four years as people have compared Donald Trump to the "Back to the Future" antagonist. That might not be a coincidence. Was he actually the inspiration for Biff?

BOB GALE: There's nothing Donald Trumpish about Biff in "Back to the Future" one. He's just the quintessential bully that's pushing people around. When Biff becomes the casino operator in "Back to the Future," part two, were we thinking about Donald Trump? Sure.

- I just want to say one thing God bless America.

BOB GALE: The guy who's arrogant and very self-centered-- absolutely Donald Trump was on our mind.

- I don't see any resemblance.

KEVIN POLOWY: How much did you guys rack your brains over the time travel element? Did you look at real science in terms of what you would attempt to incorporate?

BOB GALE: Well, obviously time travel was total, total science fiction. We didn't want to spend a lot of time on special effects, because that's not what the movie was about. As long as we keep true the laws of physics that we set up, the audience will be fine with that.

- Are you telling me that you built a time machine out of a DeLorean?

KEVIN POLOWY: From what I've read, the time machine was originally not going to be the DeLorean but a refrigerator.

BOB GALE: Yes.

KEVIN POLOWY: Why a refrigerator?

BOB GALE: It was a cool visual to have this 1952 refrigerator. But when we were in preproduction finally, Bob Zemeckis came into office one day. And he said, you know Bob, having Doc have to hoist this refrigerator in the back of a pickup truck, and drive it around, and unload it, and use a forklift, and all this stuff-- that's a lot of filming of stuff that I wish I didn't have to do. So if Doc had built the time machine into a car, I wouldn't have to shoot all that stuff. Wouldn't Doc have been smart enough to build it into a car?

I said, yeah, that's a brilliant idea. Let's do that. And he said, what if the car was a DeLorean? So it was perfect. I can't take credit for the idea, but I know a great idea when I heard one. And that was a great one.

KEVIN POLOWY: Did you guys ever seriously consider a fourth movie, a "Back to the Future 4?"

BOB GALE: No, never. It was always a trilogy. We said everything we needed to say about the characters. Doc and Marty are better people at the end of the trilogy than they are at the beginning. We thought it was very satisfying, and we didn't see any way that we could top it.

["BACK TO THE FUTURE" THEME MUSIC]