'Grease' theory says Sandy was dead throughout the film

ASCOT, UNITED KINGDOM - MAY 10: Racegoers enjoy a screening of the film 'Grease' as they attend Race, Rattle 'N' Roll Racenight at Ascot Racecourse on May 10, 2103 in Ascot, England. (Photo by Samir Hussein/Getty Images for Ascot Racecourse)

ASCOT, UNITED KINGDOM - MAY 10: Racegoers enjoy a screening of the film 'Grease' as they attend Race, Rattle 'N' Roll Racenight at Ascot Racecourse on May 10, 2103 in Ascot, England. (Photo by Samir Hussein/Getty Images for Ascot Racecourse)

By Cox Media Group National Content Desk

It's "Grease" lightning!

The classic 1978 movie starring Olivia Newton-John and John Travolta hasn't lost its popularity over the years. In fact, fans are still discussing the love story between Sandy and Danny.

<span><a href="//imgur.com/RjChFGT">A theory on the ending of "Grease"</a></span>