Story

October 13, 1931; Marty McFly wakes up in young Emmett's lab the morning after the heated argument between himself and Emmett at the Hill Valley clock-tower. Emmett is now convinced that the path of science is where his life should take him and has left for the First Annual Hill Valley Science and Technology Exposition at the Hill Valley High School to demonstrate his latest invention: a flying car. He wakes Marty with a phone call and asks him to deliver the crucial component: the Static Accumulator.

As Marty arrives at the High School, "Citizen" Brown a.k.a. "Carl Sagan" returns with the DeLorean and tries to convince Marty from preventing the younger Emmett from presenting his experiment at the expo. He attempts to steal the Static Accumulator, but fails, and Marty heads inside the expo to finish the delivery. Unfortunately, Emmett is nowhere to be found and, even worse, Edna Strickland has pulled some strings and had Emmett's exhibition shut down on the grounds of public safety.

In order to get the exhibit reopened, Marty uses a cleverly disguised recording device to get Edna to admit that she was behind the arson of "Kid" Tannen's speak-easy and turns her in to Police Detective Danny Parker. Edna makes a quick escape out of the hall with Danny right on her tail. Meanwhile, "Carl Sagan" had been distracting the younger Emmett with the promise of a lucrative business deal. When Marty catches him in the act, "Carl Sagan" knocks out Emmett with chloroform and distracts Marty long enough to hide him away inside a bathysphere on the expo floor. Marty forces "Carl's" hand by slowly suffocating Emmett inside of the bathysphere, leaving "Carl" no choice but to release his younger-self.

With Emmett safe and the exhibit re-opened, he prepares to demonstrate his flying-car to the Expo when suddenly his father, Judge Brown, storms into the building and demands that Emmett stops before he makes a fool of himself and his family. A heated exchange flies between the two and Marty is able to reconcile the pair just in time for the demonstration to go ahead. As Emmett fulfills his destiny and embarks on his life of science, Marty leaves the Expo just in time to see Edna, still pursued by Danny, steal the DeLorean away from "Carl Sagan", knocking him down as she escapes at high-speed.

Marty runs to his fallen friend, now slowly being erased as the timeline corrects itself and shows him a brief glimpse of the future: a newspaper article of "Doc" Brown receiving the Key-to-the-City for his scientific endeavors, just before "Citizen" Brown fades away for good. Emmett comes outside the building, his demonstration having not gone exactly as planned, but still thrilled with the potential for further progress. He pushes Marty for more information the real-purpose of Marty's interest in his budding scientific career and Marty tells him that everything will be explained later, tearing off a portion of the newspaper with strict instructions not to read it until a certain date. Emmett grudgingly agrees and bids Marty a fond farewell. As he heads back inside, the DeLorean reappears once more, this time driven by the genuine "Doc" Brown.

As Marty and "Doc" become reacquainted, Danny Parker returns, shocked by the appearance of another DeLorean, having just seen the one he was chasing vanish in a bright flash of light. Marty and "Doc" realize that Edna has escaped through time and can potentially destroy the entire time-stream. As they ponder their next move, Danny disappears and Hill Valley itself starts to fade from existence. Within moments, they are left standing alone in an empty valley. Unfortunately, with no way of knowing when Edna traveled to, they have no chance of fixing this catastrophic change to the timeline. They stand on the side of the road, wondering what to do next when a Truck pulls up, driven by Marty's great-grandfather William McFly. They ask him about the history of Hill Valley, but William has no idea what they were talking about, but he tells them someone in the area might know: an old hermit woman, known around the area as "Scary Mary."

With no other leads, they head to "Scary Mary's" hut, finding in the front the rusted-husk of the old DeLorean. They come to the conclusion that "Scary Mary" must be none other than Edna, long since gone senile as a result of her journey into the past. In order to set-right her mistakes, the pair must first find out what triggered her mental breakdown, and more importantly, when it happened. Using the junk lying around her yard, they slowly manage to help Edna piece together her long forgotten memories. Evidently, after she escaped from Danny Parker, after hitting 88-miles-per-hour during the chase, she found herself in the 19th Century version of Hill Valley. Initially, she found it a "paradise", governed peacefully by her ancestor Sheriff Strickland, there were no "hooligans" or debauchery to speak of. She lived under an assumed name for many years until Beauregard Tannen, father of Buford "Mad Dog" Tannen, came to town and opened a saloon. She knew what had to be done, just like in 1931 she burned down the den of vice that had sprung up in town. Unfortunately for Edna, she was a bit over-zealous and the fire soon spread, setting the whole town ablaze.

With the date in hand, Marty and "Doc" head back to July 17, 1876 to stop Edna before it's too late. They catch her in the act, but so does Beauregard. In a tense standoff, Marty manages to find a way to knock out Tannen and prevent Edna from starting the fire. Edna makes an escape in her DeLorean and "Doc" and Marty give chase in their own. Unable to reach the 88-mph on the old, dusty roads, "Doc" quickly formulates a plan to override the time-circuits using some temporal diagnostic tools and brings both DeLoreans crashing back into 1931.

Edna is quickly arrested by Danny who, after hearing her ranting and raving about time-travel, assumes her to be drunk. Marty and "Doc" head back to 1986, finally convinced the timeline is back in order. Once home, Marty tries to convince "Doc" to prevent the Estate Sale of his lab, "Doc" is confused by this: he hadn't been gone at all, in fact he had been living with Clara and his children in 1986 all along. Marty realizes that perhaps they can't always change everything back to the way it was. Suddenly, another DeLorean appears and an older Marty steps out, telling the pair that something needs to be done about the future. Before he finishes, another DeLorean and another appear, each piloted by a different Marty and each blaming each-other for screwing around with the timeline. "Doc" and Marty look at each other, realise they are not finished and fly away in the original DeLorean.

To Be Continued...

Trivia

• "OUTATIME" is the original license plate of the DeLorean before it was replaced with the barcode version in 2015.
• This episode of Back to the Future features Michael J. Fox, Marty McFly's original actor in the Back to the Future trilogy, who is playing one of Marty's ancestors, William McFly in this episode.
• Doc says he got the headsets they use to communicate to each other from one of his son's "21st century video game consoles."

PC System Requirements

Minimum:

• OS: XP Service Pack 3 / Vista / Windows 7
• Processor: 1.8 GHz Pentium 4 or equivalent
• Memory: 2 GB RAM
• Graphics: ATI or NVidia card w/ 256 MB RAM
• DirectX®: Direct X 9.0c
• Hard Drive: 2 GB Space Free
• Sound: Direct X 8.1 sound device

Recommended:

• OS: XP Service Pack 3 / Vista / Windows 7
• Processor: 2.7 GHz Pentium 4 or equivalent
• Memory: 3 GB RAM
• Graphics: ATI or NVidia card w/ 512 MB RAM
• DirectX®: Direct X 9.0c
• Hard Drive: 3 GB Space Free
• Sound: Direct X 8.1 sound device

Mac System Requirements

Minimum:

• OS: Snow Leopard (10.5.8)
• Processor: 2.0 GHz Pentium or equivalent
• Memory: 2 GB RAM
• Graphics: ATI or NVidia card w/ 256 MB RAM
• Hard Drive: 2 GB Space Free
• Not recommended for MAC Minis or early-generation MacBooks

Recommended:

• OS: Snow Leopard (10.5.8)
• Processor: 2.3 GHz Pentium or equivalent
• Memory: 4 GB RAM
• Graphics: ATI or NVidia card w/ 512 MB RAM
• Hard Drive: 2 GB Space Free
• Not recommended for MAC Minis or early-generation MacBooks