4 (4 in series)
Mary Jo Ludin
Marty wants to confront Jennifer and catches her talking with the school jock and assumes she's dating behind his back. Jennifer, who has been tutoring the jock, tries to explain the situation but Marty doesn't listen to her. Marty goes to the Browns' house and receives a message that Doc and his family are trapped in Salem, Massachusetts during the Puritan period. Taking the DeLorean, Marty brings a spare flux capacitor for the train to Doc, but the DeLorean that Marty and Einstein are in is in the water and comes out. As Doc fixes the train, Marty, Clara and the boys go to a town function. Marty spurns the advances of a young lady named Mercy and she accuses him of being a witch out of spite. Marty is condemned for being a witch without being able to defend himself. Marty is sentenced to the "water" test and Doc saves him with a makeshift scuba suit. When Marty returns home, he apologizes to Jennifer for making accusations without first hearing her side of the story.
PlotMarty McFly and Liz leave from music appreciation class at Hill Valley College when he sees Jennifer Parker with big lug Kelp, believing that she is going out with him. The Brown family was exploring the Pyramids of Giza, Egypt circa 1000 BCE (Doc says it was "about 3,000 years earlier") when they were chased down after Verne pulled a prank on the Egyptians. The flux capacitor on the Jules Verne Train is damaged by a spear and the train sends the Browns to 1692 Salem, Massachusetts. Doc sends Marty a scratch and listen postcard via a miniature time machine delivery car asking him to take the DeLorean and bring back a spare flux capacitor. Upon arrival, Doc calculates that it will take several days to repair the train with the replacement and they attempt to lie low in the town of Salem.
Marty arrives at September 23, 1692 and crashes into a lake. The DeLorean sinks to the bottom, but an inflatable device brings it back to the surface, after which Doc guides the DeLorean to a hideout with a remote control. For the past few weeks, Doc has been working with Goodman Tannen as a trash man. Tannen's daughter Mercy shows up at a town event that night. Marty's wild antics and strange tongues create gossip in the town and after he plays his harmonica, he is labeled a witch and put on trial. Marty is ordered to suffer the water test, which will determine whether or not he is lying, with either consequence being death. As Marty is thrown into the water, Goodman, Mercy, and the others watch as they believe he is drowning. Meanwhile, Marty is rescued underwater by the DeLorean which is equipped with a large pincer. Marty and the Browns return to the train and leave 1692. Back home, Jennifer tells Marty that she and Kelp were only study partners and that Marty was still her boyfriend.
- Marty's middle name is revealed when Jennifer Parker angrily confronts him as "Martin Seamus McFly".
- The DeLorean is seen from all angles during an animation sequence that takes it at high speed through the forest.
- Mercy Tannen looks like Liz who was Marty and Jennifer's friend in college. Just like Mercy, she also had a crush on Marty.
- "Oh, thanks for bringing the spare capacitor. Triple-A doesn't cover this."
- —Doc Brown
- Doc: "Welcome to Salem, Massachusetts! I had you on auto-remote. How was the ride?"
- Marty: "Great... if you want to see what I had for lunch."
- — Doc guides the DeLorean to the family's hideout
- Marty: "Doc, did you hear that? They actually believe in witches."
- Doc: "Inform me of something of which I'm not already cognizant. After all, we've already been here a month!"
- Marty: "Doc, you're a garbageman?"
- Doc: "A fascinating way to explore the Puritan culture. In addition, I've started a recycling program."
- Clara: "Where's your father? We're going to be late for the town social."
- Verne: "I hope there's something fun to do this time. Last week, all we did was play "Stack the Hymnals"."
Behind the scenes
- The DeLorean is shown to have a flotation device that can raise it from underwater, which saves Marty from drowning.
- The live segment, with Christopher Lloyd as Doc, features a demonstration of water pressure (section W of the video encyclopedia). With Doc narrating, Bill Nye punches holes in a 2-liter bottle to demonstrate that water pressure is greater at the bottom of the bottle than at the top.
- As with many Tannens, Goodman Tannen ends up in a pile of manure in 1697 — falling into a pig sty.
- Babcock, "Old Buzzard" gives Marty a C minus in Music Appreciation (Mentioned only)
- Goodman Tannen
- Mercy Tannen
- Gurdy McGoo, had a cat that met the same demise (Mentioned only)
- James Brown (Mentioned only)
- Automatic dog bather
- Dog shower and dryer
- Remote control mail time machine
- Scratch and listen postcard
- DeLorean flotation device
- Replacement flux capacitor
- Surge protector
- DeLorean pincer apparatus