Someone wants to play it again, and film purists aren't happy. Seventy years after the release of Casablanca, plans are afoot for a sequel. The project is the brainchild of Cass Warner, a Hollywood producer, who was a close friend of the late Howard Koch, one the movie's three screenwriters. She is shopping for proposals for a follow-up entitled either Return to Casablanca or As Time Goes By.
Ms Warner first discovered "treatments" for the project at Koch's New York home a few years before his death in 1995. Its plot revolves around Richard Blaine, the illegitimate son of Humphrey Bogart's Rick Blaine and Ingrid Bergman's Ilsa Lund, who were separated at the end of the original movie.
"I almost fainted when Howard gave me the treatments, because I felt like I was being handed pure gold," she told The Independent on Sunday. "At the time, he said he was too old to get representation, so I promised to one day try to get the treatments made into a film."
Adding a fresh layer of symmetry to the project, Ms Warner is the granddaughter of the founder of Warner Brothers. She originally met Koch at the University of California, Santa Barbara, and he contributed to a documentary chronicling the history of the studio made by her production company, which is called Warner Sisters.
In Koch's sequel, Richard Blaine, who has been raised in the US by Lund and her husband Victor Laszlo, returns to North Africa to find out what became of his biological father. It thereby clears up some of the unanswered questions from the 1942 film, which ends shortly after Bogart and Bergman part ways.
For the project to get off the ground, though, it must first be given the green light by Warner Brothers, which owns the rights to Casablanca. This week, Ms Warner revealed that she has met executives at the studio to discuss it.
"I showed them the treatment, and they are open to taking it on, if I can get a good script and the right director attached," she said. "So I am in that process of trying to do that. The priority is of course for it to be a good bit of storytelling."
The project is at risk, however, of being torpedoed by angry fans who frequently cite the loose ends left by the original as one of its greatest charms. They are already taking to the internet and the airwaves to voice opposition to a new film, which they believe would compromise its predecessor.
"How could they squander the mystery of its perfect ending? How could anyone fill the shoes of Bogey and Bergman? Shouldn't they just leave Rick and Ilsa alone?" began a critique syndicated by The Washington Post. Another piece, from the same source, dubbed the project "sacrilege".
A perennial fixture in the "greatest ever movie" lists, Casablanca has a cultural footprint that extends to the catchphrases "We'll always have Paris" and "Play it again, Sam" (though the actual quote is "Play it, Sam").
The chorus of opposition is thought to include Stephen Bogart, the leading man's son, who was quoted saying: "If they want to make a movie about intrigue in North Africa, that's fine, but bringing the spectre of one of the greatest movies of all time into it makes it just another feeble attempt at Casablanca 2."
Ms Warner insists, though, that most hostile comments are based on a misconception. She says she does not intend to remake the original, or cash in on its reputation, but to reignite enthusiasm for it, introducing it to a new generation of fans.
"I've created horror in the minds of Casablanca lovers," she said. "I'm sorry that's the case, because the reason I'm doing this is to put eyes back on the original film. There will be flashbacks, but it's a film about the next generation; a son going back to find what happened to his parents. I wouldn't want to touch the original for the world."