It's the most anticipated summer movie of the year, certain to send "the force" to millions of "Star Wars" fans everywhere.

"Star Wars: Episode III — Revenge of the Sith" (search) is director George Lucas' (search) sixth and final film in the series. But expect this last installment to be different.

"'I'm very happy — the film turned out very well. It's a bit of tearjerker ... it's very different from the other films. It's a bit darker," Lucas told FOX News.

Lucas said the film, the third prequel to the "Star Wars" trilogy, ties up the "first" three films.

"It's just a much more emotional story, which is what happens because it is the climax of the first trilogy. And usually the first act is the introduction, the second act is introduction of the problem and the third act is the resolution. So this is where they get to resolve everything. Plus it gets to tie into the next film," he said.

As "Sith" focuses on Anakin Skywalker's journey toward the dark side and eventual transformation into Darth Vader, star Hayden Christensen (search), who plays Skywalker/Vader, believes it's not a film for the little tykes.

"It's a gradual transition that takes place throughout the film. He does some pretty evil things to say the least. It's a much darker film and I don't know if you want your four- and five-year-olds there because it gets pretty nasty at times," he told FOX News.

Christensen stopped short of demonstrating the classic "Vader" voice, saying it couldn't be done without the right equipment.

"I don't have the suit on. You need the suit to do the whole breathing thing. You can't put the cart before the horse," Christensen said.

"Revenge of the Sith" arrives in theaters May 19.

FOX News' Mike Waco and Anita Vogel contributed to this report.