那張圖不知道被修改幾次了

http://en.wikipedia.org/wiki/Back_to_the_Future_Part_II

看這裡吧

On 26 October 1985, Dr. Emmett Brown arrives in his DeLorean time machine and persuades Marty McFly and his girlfriend, Jennifer Parker, to come with him to the future to prevent their future children from being imprisoned. Biff Tannen witnesses their departure. They arrive on 21 October 2015, where Doc electronically hypnotizes Jennifer and leaves her incapacitated in an alley. Doc has Marty pose as Marty McFly, Jr., his son, to refuse an offer to participate in a robbery with Biff's grandson, Griff.