Doc Brown returns for Back to the Future anniversary

Back to the Future saw the eccentric Emmett 'Doc' Brown, played by Christopher Lloyd (right), take Marty McFly, played by Michael J Fox, back to 1955

Back to the Future's Christopher Lloyd has returned as inventor Doc Brown to celebrate the date on which he and Marty McFly first arrive in the future.

Lloyd has made the short film Doc Brown Saves the World, marking the 1985 film's end date of 21 October, 2015.

Universal has released a teaser for it, to be included in the 30th anniversary re-issue of the full Back to Future trilogy.

Michael J Fox, who played student Marty, does not feature in the teaser.

Lloyd's eccentric time-travelling inventor Emmett "Doc" Brown is seen getting out of the film's now legendary DeLorean time machine sports car.

What then goes on to unfold is left for fans to conjecture, in true "teaser" style.

Earlier this year, Lloyd also reprised the role in another teaser, this time for the video game Lego Dimensions.

Michael J Fox's Marty has to make sure his mother drops her crush on him to marry his father

The 30th anniversary re-issue has other extras, including a 2009 retrospective documentary on the trilogy and two episodes of the animated spin-off.

It will be released on 21 October.

The comic science-fiction Back to the Future films followed the adventures of Marty and the scatty inventor.

In the first 1985 film, teenager Marty is sent back in time to 1955, where he meets his future parents, then high school students.

His mother-to-be forms a crush on him, an infatuation he has to quash in order for his parents to fall in love.

The end of the movie sees Marty returning to his original timezone, where together with the inventor Doc Brown, he travels to 21 October, 2015.

The film became the highest-grossing of 1985, making more than $300m (£197m) worldwide. It also received four Academy Award nominations, winning one Oscar for sound effects editing.

Two sequels were made, Back to the Future Part II, set in 2015, and Back to the Future Part III, set in 1885.