The last time we saw Dr. Emmett "Doc" Brown was at the end of 1990's Back to the Future, Part III, where he bid Marty McFly a fond farewell before departing 1985 for times unknown with his new family in a stylized time-traveling hovertrain. Since then, "Back to the Future" fans have yearned for another installment of Robert Zemeckis's epic science-fiction adventure trilogy, which ranks high on our list of the greatest (and highest grossing) movie franchises of all time. Prospects of a fourth sequel seemed dim: In November 2010, screenwriter Bob Gale insisted that neither he nor Zemeckis had any plans for a new Back to the Future film.

But a new video, featuring a frazzled Christopher Lloyd emerging from a reconstituted DeLorean (wasn't it destroyed at the end of Part III?) raises new hopes. Shot from the first-person, home-movie perspective that defined the viral trailers for J. J. Abrams's Cloverfield, Doc Brown startles a Spanish-speaking couple before parking in the entrance to a movie theater. "What year is it?" he asked, eyes wide. "2011? Great Scott!" While there's no sign of Michael J. Fox, a quixotic Lloyd in his full-body radiation suit should excite Back to the Future fans everywhere.