- " Doc turned around [in the driver's seat of the DeLorean]. The dog was playing with something in the backseat. / "Einie, get that junk out of your mouth!" / Doc pulled the crumpled silver bag from between Einstein's teeth. / A silver bag? Something tugged at the back of Doc's mind. Where had he seen a silver bag before? Where did that dog find this stuff, anyway? "
- —From Back to the Future Part II by Craig Shaw Gardner (quote, page 95)
After discouraging Marty from using the almanac or the DeLorean time machine for financial gain, Dr. Emmett Brown disposed of the bag, with the book and receipt still inside, by throwing it into a trashcan, rather than making use of a Litter Bug that happened to be nearby, where it was found shortly afterwards by Biff Tannen.
Doc discovered the bag, still containing the receipt, and which he had earlier found Einstein playing with, in the DeLorean time machine, along with the top of Biff's cane, after he, Marty and Jennifer left 2015 for 1985, but instead found themselves in a nightmarish alternate reality.
Behind the scenes
- The novelization describes Einstein as playing with the bag in the backseat of the DeLorean (see Quote above), but there is no backseat in a DeLorean — which leaves one wondering if this was a case of artistic license by Craig Shaw Gardner or simply an error.