- "There it was, the wire running down from the clock tower [of the Hill Valley Courthouse] to the lamppost, and the toolbox on the trailer, sitting next to the DeLorean hidden under the tarpaulin. It gave Doc a thrill just to see everything set up again. Wasn't science wonderful?"
- —From Back to the Future Part II by Craig Shaw Gardner (quote, page 162)
A tarpaulin was a large sheet of heavy waterproof fabric.
On November 7, 1955, Emmett Brown and Marty McFly used a tarpaulin at Doc's garage to cover the DeLorean time machine when Lorraine Baines called round to ask Marty to take her to the Enchantment Under the Sea dance at Hill Valley High School on November 11.
The tarpaulin was also used to hide the DeLorean on Doc's flatbed trailer in Courthouse Square for the 'weather experiment' that same night.
During Doc and Marty's second visit to 1955, Doc narrowly avoided coming to face-to-face with his younger self, who had been working inside the car and suddenly emerged from beneath the tarpaulin to ask him to pass over a ⅜ wrench from the toolbox on the trailer to tighten the flux capacitor. (Strangely enough, Doc was at the time warning Marty via walkie talkie to be careful not to run into his other self at the dance.) Fortunately, Doc managed to avoid any disastrous consequences by pulling his hat down over his head, disguising his voice and keeping his back to his 1955 self — as well as correcting the younger Doc's request for a ⅜ inch wrench to a ½ inch; and engaging in polite conversation with 1955 about the 'weather experiment' and the forthcoming thunderstorm so his younger self would not get suspicious.