One of the scariest horror movies ever made, 1973's "The Exorcist," spawned two uneven sequels. Now it's time to try again.

"Exorcist: The Beginning," which is a prequel to the original, opens this weekend, and the backstory is enough to make your head spin.

When it comes to movie curses, this one could take the cake: First, the prequel was made twice before it was even released. Its original director died, his replacement was fired and its final director was struck by a car during the shoot. It changed casts and its budget more than doubled.

"Some people do say that this is kind of a cursed movie," the film's final helmer, Renny Harlin (search),  told Fox News. "So to follow in that kind of logic, I got hit by a car and I broke my leg pretty badly, and I had to shoot the whole movie on crutches with a cast on my leg."

In the original "Exorcist," Regan, a 12-year-old girl, was possessed by an ancient demon. Two priests confronted it — young Father Karras, who was losing his faith, and aging Father Merrin, whose past clashes with evil had strengthened his spirit but weakened his body.

The prequel tells the history of young Father Merrin, following him to post-World War II Africa where he encounters the demon Pazuzu.

"I love horror films, and 'The Exorcist' is the ultimate horror film, so the opportunity to do a prequel — and, in a way, try to set up a lot of those mysteries and things that were in the original 'Exorcist' by doing this prequel — was a great opportunity for me," said Harlin. "I'm trying to do an homage to 'The Exorcist' and also take the audience to somewhere new as well."

But it wasn't an easy road getting there.

Way back in February 2001, it was announced it that casting for a prequel was under way. The script had been penned by "Terminator 2" co-screenwriter William Wisher Jr., and then rewritten by "The Alienist" author Caleb Carr (search ).

John Frankenheimer (search), director of the original "Manchurian Candidate," was signed on to the movie in August 2001. Liam Neeson (search ) was cast as Merrin.

After nearly a year of preproduction, Frankenheimer, 72, backed out of the film three months before shooting was to start. He then underwent back surgery, which led to a stroke. He died about a month later.

The resulting two-month delay caused Neeson to quit due to prior movie commitments.

Paul Schrader (search), who directed "Affliction" and wrote "Taxi Driver" and "Raging Bull," took over from Frankenheimer. Stellan Skarsgård (search ), whose credits included "Good Will Hunting" and "Deep Blue Sea," was cast in the Merrin role.

Things seemed to be back on track. Filming began in Morocco in late November 2002. Schrader says he inherited Frankenheimer and Carr's approach to the story.

"The thought at that time was to do more of a character piece about the young Merrin, and less of what we would refer to as 'spinning heads and pea soup,'" Schrader told The Associated Press. The script was more spooky than gross-out.

Schrader had finished everything but the music when he turned over his final cut to Morgan Creek production chief James G. Robinson last year.

It didn't go over well.

"In the end, he decided they should have made a more conventional horror film," said Schrader, who was fired from the flick.

A new batch of directors were approached to shoot more scenes that might punch-up the scare factor — until they met with Harlin, who had a different idea.

The Finnish director, who made "Die Hard 2" and "Cutthroat Island," had a longshot proposal: Re-shoot Schrader's entire movie, replace some actors, drop characters and revise the plot.

"They said, 'See you later!' And I thought I was home free," Harlin said. "So I went home and started relaxing, and all of a sudden I got a call and they said, 'We really thought about your idea of redoing the whole movie and that's a really great idea. Let's do it.'"

Including the $35 million that Schrader had already spent, Harlin's remake pushed the total production cost reportedly north of $90 million.

Most of the actors were replaced, but Skarsgård kept the Merrin role — although he changed his approach.

"The first one we did was more of a psychological thriller, basically about a man in crisis," Skarsgård told the AP. "For the Renny Harlin movie ... I changed the performance, I even changed the makeup actually. You have to adapt to the material and the kind of film you're doing."

Both versions will likely turn up on DVD in the coming months.

Schrader wants his film to be seen, but is cynical about the combo DVD package.

"The reason my version will see the light of day, if it does, is not because of fan push, or any high motivations," he said. "It's just because there's a buck to be made."

Shortly after starting the reshoot, Harlin was hit by a car in Rome and his leg was pulverized. Still, the actors said Harlin's artistic vision wasn't affected by his injury.

"He's incredibly competent with the camera," James D'Arcy, who plays Father Francis, told Fox News. "I've never seen anybody sort of throw the camera around so happily and without any worries of, 'Oh how do I cut that scene together.' He absolutely is the master."

The original 'Exorcist' is a modern classic. Despite its horror genre — complete with scenes where Regan projectile-vomits a green "pea-soup" fluid and rotates her head 360 degrees — it collected 10 Academy Award nominations, including one for best picture. It won for best adapted screenplay and best sound.

However, "Exorcist: The Beginning" may not be so lucky. The movie did not screen for critics, which usually means a studio has little confidence in a picture.

Still, horror fans will likely plunk down their $10 at least out of curiosity — and the cast is happy to have revived the demon once again.

"It's a little bit scary of course to want to be a part of a prequel because obviously it's going to be very difficult to get it better than the first one," Izabella Scorupco (search ), who plays Dr. Sarah Novack, told Fox News. "But at least if we can breath a little bit of its air and be a part of it, and [be] as good as possible, it's just amazing."

The Associated Press contributed to this report.