The creator of Grease has finally weighed in on that crazy 'Sandy is dead' fan theory.

It’s the Grease fan theory that’s been widely circulating social media this week after Sarah Michelle Gellar posted about it on Facebook: Was Sandy dead for the whole movie?

Aside from sounding like the kind of narrative I once wrote as a nine-year-old, sloppily whacking on the line, “Oh, and then I woke up and it was all just a dream” to the end of any story to give it that primary school sense of credibility, the Reddit-spawned theory did have legs.

Weak legs, but legs at that.

Maybe Sandy did actually drown in that first scene by the beach with Danny. And then maybe over the course of the movie, we explored her dying dream as she slowly lost consciousness — this, apparently, explaining the film’s gradual distancing from reality as it becomes more dream-like in feel, and the car’s ascension into the sky at the end representing her death.

Grease creator Jim Jacobs has now weighed in on the bizarre theory with TMZ, debunking the theory and putting thousands of Reddit conspiracy theorists out of a... job? (Did nobody think to give him a call to simply just ask the question before the guessing game went viral..?)

Although Jacobs acknowledged there are differences between the book and the movie, one thing is certain and that is the notion that the movie was not just based on dream.

"Sandy was very much alive," at the movie's end, he confirmed to TMZ in an attempt to put the entire theory to bed.

Jacobs also went on to eloquently declare that whomever came up with the Sandy-is-dead rumour "must have been on acid."

Joy. Guess that one's sorted?