When Doc shows up to take Marty and Jennifer to the future to help their children things go wrong and Biff makes matters worse as he goes back to 1955 with something that can change the entire outcome of his future. Marty sets out to save his son from making a deal with Griff that could land him in prison and the events similar to 1955's chase. Meanwhile, Jennifer is mistaken for her future self and is transported home by the police. When Jennifer wakes up and discovers her future isn't exactly what she had hoped.
