This movie begins where Back to the Future ended; with Marty, Doc and Jennifer going into the future to help Marty and Jennifer's children. After doing that they return to 1985. But when they arrive they discover that things are not as they remember it. There's a casino which is owned by, of all people, Biff. Marty learns that his father was killed a few years ago and his mother is now married to Biff. Marty meets with Doc who thinks he knows what happened. Somehow Biff got his hands on a book from the future which has in it all sports results and he used it to bet on sports and amass his fortune. Marty said he considered doing that but Doc nixed it. Somehow the Biff from the future discovered about the time machine and Marty's plan and used the time machine to give his younger self the book. So they have to find out when Biff got the book so they can take it away from him. So Marty goes to see him and confronts him about it and Biff also tells him that he was the one who killed George. Marty and Doc then go back to, of all places, 1955 on the day of the school dance. So Marty tries to get the book while trying to avoid being seen by Doc's younger self and himself who's getting ready to go back to 1985. Marty at times gets the book but when Biff calls him a coward, Marty gets incensed which leads to him losing the book so he has to try and get it again.