At the end of 1985’s Back to the Future, Doc Brown corralled Marty McFly and his girlfriend Jennifer Parker into his time-traveling DeLorean before delivering the soon-to-be-iconic line, "Roads? Where we're going, we don't need roads." At that point, the car soared into the sky, flying off to parts unknown. The trio’s destination was revealed in a sequel that hit theaters November 22, 1989, in the form of Back to the Future II.

Despite the first film’s cliffhanger, another entry wasn’t initially in the cards. However, when the original Back to the Future became the highest grossing movie of 1985, studio execs saw the chance for further profit, an outlook common in a sequel-filled decade that had seen Rambo, Rocky, Jaws, Halloween, Star Trek and dozens more capitalize on the triumph of their predecessors.

Director Robert Zemeckis and writer/producer Bob Gale agreed to return for a second film, with one caveat. "We said, 'If Michael J. Fox and Christopher Lloyd will sign on for a sequel, yes we'll do a sequel,'" Gale recalled in a documentary covering the Back to the Future films. "Because if we have Marty and Doc, we can figure a story out. If we don't have those guys, there's no movie." Both actors were eager to reprise their roles, setting events in motion for a second film.

Once the principals of the original were signed up, an add-on was made to the final scene of the 1986 home video release of Back to the Future which saw a “To Be Continued…” title card flash on the screen as “Back in Time” by Huey Lewis and the News kicked in.

The sequel's plot would see Doc (Lloyd), Marty (Fox) and Jennifer (Elisabeth Shue) voyage to 2015 to stop Marty Junior from partaking in a robbery that would set off a disastrous chain of events for the McFly family. Initially the mission is a success, as Marty thwarts his future son’s involvement by posing as him and turning down the illegal activity. However, Marty sets in motion a new series of events when he picks up a sports almanac for the years 1950-2000 with plans to use the book's information to make money by gambling when he gets back to 1985. Doc finds out and lectures the teen on the dangers of such a scheme before tossing the book into the trash. Unbeknownst to them, an elderly Biff Tannen (Thomas F. Wilson) is eavesdropping. While the pair go off to find Jennifer, who Doc had tranquilized to keep from asking about the future, Biff grabs the almanac and delivers it to his 1955 self.

Marty and Doc return to 1985 and leave a passed-out Jennifer asleep on her porch, but soon discover that all is not well. The neighborhood is an apocalyptic wasteland where gangs rule the streets and crime is rampant. It turns out Biff has parlayed his sports betting into an empire and has married Marty’s mother. His real father, George McFly, died years earlier when he was shot in an alley – by Biff, it turns out – on his way to receive an award for writing. The task for Marty and Doc is clear; they must go back to 1955 and retrieve the sports almanac from young Biff, thus preventing this horrific alternate future.

The movie's scenes are then brilliantly cut with the 1955 scenarios played out in the first film as Marty dresses the part of a spy in sunglasses, black leather jacket and fedora to case Biff with the almanac, all while the events at the 'Enchantment Under the Sea' dance from the original Back to the Future are taking place. Using a hoverboard brought with him from 2015, Marty is able to hold onto Biff’s speeding car and retrieve the sports book. He’s then saved from certain death by Doc who pulls him out of harm's way using the flying DeLorean moments before Biff would have run the teen over.

Marty burns the almanac to ashes. Just as he is about to board the DeLorean alongside Doc to head back to 1985, the hovering car is struck by lighting and disappears.

A bewildered Marty stares at the empty sky as a heavy rainfall descends until a car drives up to him and a man from Western Union gets out and presents him with a letter. It’s from Doc, who got zapped back to 1885 and is living happily. Marty rushes back into town to find 1955 Doc, who has just sent Marty – from the original movie – back to 1985. Marty tells his shocked scientist friend that he is back from the future, causing Doc to faint as the words “To Be Concluded…” flash on the screen.

No matter what happened with Back to the Future II at the box office, there was going to be another one as indicated by a minute-long trailer shown before the credits ran. II and III were filmed back-to-back, with the latter set in the Old West where Doc Brown ended up at the conclusion of the second.

Back to the Future II didn’t do gangbusters like the first one, but it more than held its own with a domestic gross of nearly $118.5 million, placing it in the top five for the year. The film didn’t come without controversy as two main characters were replaced. Claudia Wells, who played Jennifer in the original, had taken a hiatus from acting to care for her sick mother and was replaced by Shue. Crispin Glover, who played George McFly in Back to the Future, was also replaced after a contract dispute, but filmmakers used archival footage as well as a cast of his face to mold a likeness onto a replacement actor, Jeffrey Weissman. The former sued Universal Pictures in a landmark lawsuit. The resultant ruling changed how Screen Actors Guild members were compensated for likenesses and archival footage going forward.

Conspicuously absent from the movie was a rock and roll song tie in. Back to the Future nailed it with Huey Lewis and the News’ “Power of Love,” while the third installment had the ZZ Top single “Doubleback.” Conversely, Back to the Future II was almost entirely scored. Sammy Hagar’s “I Can’t Drive 55” plays for a bit when Marty arrives at Biff Tannen’s Pleasure Paradise in the dystopian 1985, but the track was never used to promote the film.

Much has been made in recent years about what the movie got right about the year 2015. We’re still waiting for hoverboards that work like they did onscreen, self-lacing sneakers aren’t widely available just yet and there’s no indication cars will be flying anytime soon. However, biometrics like fingerprint and retina scans are a thing, as is a baseball team from Miami. And as laughably unlikely as it was at the time, the film was just one year off in predicting the Chicago Cubs would win the World Series, which they did in 2016 for the first time in 108 years.