'Grease' turns 40: John Travolta discusses the viral fan theory that Sandy is really dead

John Travolta is a big fan of that Grease Internet theory that went viral — that co-star Olivia Newton-John's Sandy is actually dead in the film.

Morbid, yes. But worldwide debate around the premise proves how powerfully the 1978 classic musical, which starred Travolta as greaser Danny, resonates as it turns 40 on June 16.

"I love it; imaginations are awesome," Travolta, 64, tells USA TODAY on a call from France, where he celebrated the movie's anniversary with a screening at Cannes Film Festival (a newly restored Blu-ray is out now). "These things are bound to happen to something timeless like this. It's so fun."

Travolta was fascinated when the theory went viral in 2016. It speculated that Sandy drowned while frolicking with Danny on the beach at the start of the movie — and the entire story is her coma fantasy. 

More:Danny and Sandy finally get their movie-ending 'Grease' kiss

Earlier:'Grease' fans shut this horrifying, viral conspiracy theory down

This would explain Danny's boast to his male friends, “I saved her life; she nearly drowned" on the song Summer Nights. And the happy duo flying their convertible into the clouds for the famous ending signified Sandy ultimately dying.

Does the theory work for Travolta? "I could have fun with it," he says. "But I know the writers of Grease, and I was around in the original days. I can’t take it too far."

Danny is exaggerating when he says he saved Sandy's life, Travolta points out.

"He's bragging; it was made up to impress the boys," he says. "(Sandy and Danny) have two different stories and somebody is lying. Most likely, it's Danny.

"But I don't want to spoil the fun for everyone," he adds.

The actor believes that, somewhere, Sandy and Danny are still together.

"I think they had several kids, which people did in those days, they adored their kids, and they held onto their romance," says Travolta. "Sandy and Danny were the real deal.”

Director Randal Kleiser has kept silent on the fan theory, promising to reveal his answer at length in a planned book. But he dismisses Sandy's flight to heaven "as the reason for the ending."

Kleiser took advantage of the anniversary to oversee the full restoration of Grease. A clip of Sandy and Danny sharing a kiss in that flying convertible, intended to close the movie, is included as a bonus feature in the DVD and digital HD release. 

The director was also able to make a small fix that had annoyed him (and fans) for years: digitally repairing the blurred-out sign behind Sandy and Tom (Lorenzo Lamas) in the Frosty Palace malt shop.

Producer Allan Carr had a deal to feature Pepsi in Grease. But the prop manager didn't get the memo and put a Coca-Cola sign in the Frosty Palace, according to Kleiser.

Carr blew a gasket when he saw the scene after production wrapped. 

"He made us blur it with 1978 technology, which looks terrible," says Kleiser. "Fans have always asked what happened. It was simply because they screwed up and put Coke signs there."

The altered sign makes Pepsi the clear winner 40 years later.

"Randal has been wanting to fix the Coke sign since the day Grease was released, it drove him crazy," says Andrea Kalas, vice president of Paramount Pictures archives, who oversaw the year-long restoration. "We now have the technology to do it seamlessly."