- " Marty could could see that there was no use arguing with him [Doc]. Nevertheless, the desire was still in him to convey the warning. / "Yeah, Doc...I see," he nodded. "Listen, I'm gonna get a candy bar. You want anything?" / "No, thanks." / Marty turned and went into the cafe nearby. He purchased an Almond Joy bar from the perennially scowling counterman and also bummed a piece of paper and envelope. Then he sat at a booth and composed a brief note to Doc. "
- —From Back to the Future by George Gipe (quote, pages 195 and 196)
- " "Were you wearing that [the bulletproof vest] all along?" Marty asked. / "Sadly, no," Doc Brown replied. "The first time around, I must have been taken by surprise. No, my boy, it was your warning that saved me." / With that, he reached into his pocket and pulled out the letter that Marty had written in 1955. It was yellow and brittle, the scotch tape holding it together withered and ready to fall apart. / Marty smiled and shook his head. "What a hypocrite," he said. After all that lecturing about screwing up the space-time continuum..." / "Yeah, well, I figured what the hell..." "
- —From Back to the Future by George Gipe (quote, pages 239 and 240)
On November 12, 1955, Marty McFly, before returning to 1985, wrote a letter to Dr. Emmett Brown on stationery from Lou's Cafe, using a fountain pen, and sealed it in an envelope marked Do not open until 1985.
Marty placed the letter in Doc's coat pocket. However, when Doc discovered the letter, he tore it up as he didn't want to alter the future and placed the pieces back in his pocket. However, sometime during the thirty years before the event, Doc stuck the letter back together with scotch tape and read it. Following its instructions, he wore a bulletproof vest on the night of the world's first temporal displacement. When Marty arrived back in 1985 and discovered that his friend was still alive, Doc produced the letter — now yellow with age — from his inside pocket.
Dear Dr. Brown,
On the night that I go back in time at 1:30 A.M., you will be shot by terrorists.
Please take whatever precautions are necessary to prevent this terrible disaster.
Doc Brown — On October 26, 1985, at about 1:30 a.m., you will be shot by terrorists at the Twin Pines shopping mall parking lot. Please take whatever precautions are necessary to prevent this terrible disaster.
Your friend, Marty. November 12, 1955
Behind the scenes
- In the novelization, Marty marks the envelope Do not open until October 1, 1985 rather than Do not open until 1985 as seen on-screen.
- Bob Gale was surprised to get a letter from a young fan in Japan who pointed out that Marty's letter looked different in 1985 than it had in 1955. "Some people don't have enough to do, I guess," commented Gale. Basically, the letter in the first scene concludes with four lines ("Please take whatever/ precautions are necessary/ to prevent this terrible/ disaster"); when Doc taped it back together, the same sentence was on three lines, as seen in the image above. Like the DeLorean odometer, the McFly family candy jar, and the flaps on the shirt pockets, the letter is one of the continuity errors that fans of the films enjoy spotting.
- After 2001, in light of the 9/11 terrorist attack on the Twin Towers in New York, whenever Back to the Future was shown on television, the scene in which Marty is reading his letter was sometimes edited so that he says, "Dear Dr. Brown, on the night I go back in time you'll be shot. Please, please take whatever..." (The words "by terrorists" were redubbed with "please" and were digitally erased from the letter when it was shown on-screen in close-up.)
- In LEGO Dimensions, Marty puts a shopping list on Doc's fridge instead.
- Doc's willingness to read the letter may have been foreshadowed by two separate moments in the film. First, when Marty finds Doc repeatedly watching the part of his videotape where 1985 Doc tells Marty that "they found me" and to run with clear panic. Second, while Doc initially tears up the letter, when Marty tries to tell Doc about the future while he is on the clock tower ledge, Doc is clearly listening before Marty is interrupted and must leave before he runs out of time.