Justin Long Geeks Out About 'Back To The Future'

"Back To The Future" is one of pop culture's most referenced touchstones, one everyone knows and loves — and we mean everybody, including actor Justin Long.

The 1985 comedy hit stars Michael J. Fox as Marty McFly, a teen who accidentally travels back in time to 1955 in a time machine invented by a slightly mad scientist (Christopher Lloyd). During his trip back in time, Marty must make sure his teenage parents-to-be meet and fall in love, in order for him to get back to the present day and avoid erasing his own existence.

Long, whose films "A Case of You" and "Best Man Down" open this month, is a huge fan of McFly and Friends, and has the Christopher Lloyd and Michael J. Fox impressions to prove it. When Long sat down with MTV News' Josh Horowitz for "After Hours," he not only showed off his expert impersonations, but also totally geeked out, answering trivia questions about the movie with the greatest of ease.

Check out the clip above, and look for "A Case of You" and "Best Man Down" this month.