*ahem*
"..As they depart, Biff Tannen accidentally witnesses their departure. They arrive on October 21, 2015, where Doc electronically hypnotizes Jennifer and leaves her incapacitated in an alley. Meanwhile, Doc has Marty pose as Marty McFly, Jr., Marty's future son, to refuse an offer from Biff's cybernetically-enhanced grandson, Griff Tannen.." :D