A fan theory that is spreading across the web like wildfire will change the way Grease fans watch the cult film forever.

According to Reddit user atomicbolt, hidden clues throughout the 1978 musical including the opening and closing scenes and song lyrics reveal the devastating truth of the 1950s love story – that Sandy is dead.

And instead of going off into the sunset with her soulmate Danny Zuko, the clean-cut Aussie student is actually ascending into heaven.

In a post from 2013 that has resurfaced on social media, Atomicbolt highlighted the last scene where Sandy and Danny leave their school carnival and get into a red convertible.

But rather the simply drive away, the car promptly defies the laws of gravity and flies into the sky.

Atomicbolt asks: ‘How did the car fly?’

You see, at the beginning of the film, we see Danny and Sandy meeting on the beach.

Later, they said, ‘Danny explains through song that they first met when Danny ‘saved her life – she nearly drowned.’

The fan theory?  ‘Sandy actually did drown on the beach that day.

‘As she drowned, her brain deprived of oxygen, she had a vivid coma fantasy involving her summer fling Danny, where they shared a magical year of high school together.

‘The visions get increasingly outlandish as time passes, until finally, as Danny desperately tries to resuscitate her on the beach, she sees herself flying into Heaven in her dying moments.

‘The entire movie was a drowning woman’s coma fantasy.’

There you have it.

After this was posted, other joined in and Reddit user Randomd0g gave their own version of what happened during the film.

They reckon that Sandy kills herself towards the end of the movie and that the entire last scene is her dying thoughts or a dream sequence of some kind.

The evidence?

‘The last line of ‘Look at me I’m Sandra Dee (Reprise)’ is ‘Goodbye to Sandra Dee’.

‘Everything that happens in the last scene is just a little TOO perfect.

‘Danny and Sandy are back together despite everything, Rizzo SUDDENLY isn’t pregnant AND Kenickie suddenly decides that he actually loves her, the geeky kid gets onto the sports team, EVERYTHING is suddenly ok, just the way that sweet, innocent Sandy would have wanted it to be.

‘And in the last shot of the movie, she flies up to heaven with her dream boyfriend in her magic flying car.’

Source: Grease fans go into meltdown over theory that Sandy is DEAD all along