All's well in the new and improved McFly household, and teenager Marty -- barely recovered from his exhilarating sojourn to 1955 -- and his sweetheart Jennifer are about to resume a normal life when Doc Brown arrives in the DeLorean time machine. The wigged-out scientist tells the couple that they are urgently needed in the future. Soon, all three are propelled to 2015, where Marty must prevent a crime involving his teenage son that would bring disgrace to the future McFly family. Unaware of the previous adventure, Jennifer is put into a state of suspended animation. Marty assumes his son's identity to rebuff the hectoring of Griff, the chip-off-the-old-block grandson of the original's bully, Biff. Marty outwits the punkish Biff and his gang, eluding them via a Mattel hoverboard when they give chase, and thereby saving the McFly name.