One element of Back to the Future Part III‘s ending still doesn’t sit right with me. Robert Zemeckis and Bob Gale’s iconic trilogy wraps up with Marty McFly, now safely back in 1985 with Jennifer, receiving a surprise visit from Doc Brown, who has constructed a time-traveling steam train to carry his new family through the time-space continuum. Marty and Doc’s heartwarming farewell ensures the Back to the Future trilogy ends on an uplifting, wholesome note, with Doc reaffirming to his young friends – and, by extension, the audience – that their futures are whatever they make them.
Back to the Future Part III never explains exactly how Doc Brown builds a steam train time machine while trapped in 1885, although a comic sequel helpfully fills in that gap by attributing his invention to the hoverboard Marty left behind. The more important question, however, is not how Doc Brown constructs the decade-hopping locomotive, but why. From one perspective, Doc’s train can even be viewed as a betrayal of his Back to the Future character across the three movies.
Doc Brown Wanted To Destroy The DeLorean In Both Back To The Future Sequels
Doc Brown Had Officially Decided To Retire From Time Travel
While Doc Brown is thrilled about his temporal tampering in 1985’s original Back to the Future movie, he gradually comes to regret that decision in the sequels. After witnessing Biff’s manipulation of history using the sports almanac in Back to the Future Part II, Doc Brown resolutely decides that, after normality is restored and everyone is safely back home, the DeLorean should be destroyed. The line in question goes, “The risks are just too great, as this incident proves. And I was behaving responsibly. You can imagine the danger if the time machine were to fall into the wrong hands.”
More than just a fleeting concern, Doc Brown doubles down on decommissioning his time machine in Back to the Future Part III, insisting to Marty, “As soon as we return to 1985, we’ll destroy this infernal machine.” While Back to the Future is hardly an introspective character study, Marty McFly and Doc Brown do each learn to become better versions of themselves over the course of the trilogy. Marty stops getting riled up by insults and “chicken” jibes, while Doc Brown recognizes that no one should have power over time, and his own scientific hubris must not take precedence over others’ lives.
Doc Brown Wanting To Destroy The DeLorean Was Vital To His Story
Doc Brown Thought “What The Hell?”
The real issue with Back to the Future Part III‘s ending, isn’t figuring out how Doc cobbles a time machine together in 1885, but why he performs a moral pivot and decides to build another time machine after previously declaring the DeLorean too dangerous to even exist. Back to the Future Part III fails to offer a suitable explanation.
Without a worthwhile explanation, it simply feels like Doc Brown relapses into old scientific habits.
Doc mutters something about needing to pick up Einstein, but the excuse doesn’t hold up. Christopher Lloyd’s character had already resigned himself to remaining in the Wild West at the start of Back to the Future Part III, and gave no thought to Einstein then. In any case, Doc could trust that Marty would take good care of the dog in 1985.
The train featured alongside a newly-built DeLorean in Back to the Future: The Animated Series, which took place after Part III.
Without a worthwhile explanation, it simply feels like Doc Brown relapses into old scientific habits. Doc knows that building another time machine risks another almanac incident, or worse, but seemingly finds himself consumed by curiosity and the challenge of designing a DeLorean replacement in an era with minimal technology. If Doc Brown really does construct the flying steam train for selfish reasons, that completely negates the character journey he experiences across Back to the Future Part II and Part III, in which he puts his own ambitions aside for the sake of protecting history.
Why Doc Brown Might Have Built A Time Machine Again In Back To The Future Part III’s Ending
Doc May Have Had His Reasons
There are a few ways Doc Brown’s DeLorean train can be reconciled with his insistence that time machines shouldn’t exist from earlier in the Back to the Future trilogy. Ignoring Back to the Future‘s wider media released after Part III, one could argue that Doc intends to destroy the train after making his single trip to 1985. Perhaps the idea is just to pick up Einstein, say one last farewell to Marty, then return to 1885 and send the train crashing over a canyon.
Perhaps he realized the best way to protect his new family was to remove them from the timeline completely.
It’s possible that Doc takes more precautions with his steam train than with the DeLorean. Having seen how easily Biff stole the car and changed history in Back to the Future Part II, Doc may ensure the train is harder for an outsider to commandeer. Stealing a locomotive is less straightforward than stealing a car, after all, so with a few security tweaks, Doc might rule out the possibility of his new time machine falling into the wrong hands.
Finally, Doc Brown’s new time machine might have been necessary to protect his family. Clara Clayton, his wife, was supposed to die but for the intervention of Doc and Marty in 1885, meaning her survival already altered the natural flow of history. Doc and Clara having children together at the end of Back to the Future Part III pushes the timeline even further off course, so perhaps he realized the best way to protect his new family was to remove them from the timeline completely and travel through the time vortex forever, never settling in one place long enough to affect history.
