- "Doc opened the gull-wing door [of the DeLorean time machine]. Someone barked. Marty looked in past the inventor's shoulder. Doc's sheep-dog was in the car! / 'Move over, Einstein!' Doc Brown said in the same [lecturer] tone he had used with Marty. / Marty circled to his side of the car, opening his own door. / 'Einie!' he called. 'Where did you come from, boy?' He climbed into the car next to the sheep-dog, and realized he was still holding onto the hoverboard. He stuffed the flat, pink gizmo behind the passenger seat. / 'I'd left Einstein here in a suspended animation kennel when I went back to 1985 to bring you here,' Doc explained. 'He never knew I was gone!' He reached over and ruffled the dog's fur. 'We'll be home soon, boy. Just sit tight.' "
- —From Back to the Future Part II by Craig Shaw Gardner (quote, page 59)
A suspended animation kennel was a device invented by the early 21st century that allowed animals to go into suspended animation while their owners were away. When the animals woke up, it was like only a day had passed.
Emmett Brown placed Einstein in a suspended animation kennel in 2015 after finding out about Marty McFly's children, Marty Jr. and Marlene, and retrieved his pet while Marty was running from Griff Tannen.
Behind the scenes
- The plot point was added to explain why Doc left with Einstein in 1985 on his trip to the future, then came back without him on his return from the future.
- Suspended animation kennels have yet to be invented.
- Back to the Future Part II (Mentioned only)