LOS ANGELES — What a who's who list Hollywood has lined up for its summer action spectacles: Wolverine. Transformers. Harry Potter. James Kirk. G.I. Joe. Terminator.

If there's one word to sum up it all up, it's this: Relentless.

Starting May 1, barely a weekend will pass without another brawny special-effects extravaganza landing in theaters.

Appropriately, summer starts with a couple of prequels.

After co-starring in three "X-Men" adventures about the Marvel Comics mutants, Hugh Jackman steps out from the pack for "X-Men Origins: Wolverine." The film spins the back story of Jackman's metal-clawed loner, a military experiment gone rogue amid a government conspiracy to control his super-freak kinfolk.

Next, the starship Enterprise is relaunched in "Star Trek," with a new cast taking on the characters originated in the 1960s TV show. Chris Pine inherits William Shatner's role as dashing James Kirk, while Zachary Quinto plays Vulcan egghead Spock (Leonard Nimoy, who created the role, pops up as the older Spock).

Like "Star Trek" director J.J. Abrams, Pine grew up more a "Star Wars" kid than a "Star Trek" kid. After snagging the role, Pine started watching the original series but stopped halfway through the first season.

"It was kind of nice to familiarize myself with the world, but it didn't help me much at all to delve any deeper," Pine said. "If anything, it was a hindrance to kind of watch what Mr. Shatner had done because he'd done it so well, and he was so specific.

"There were certain mannerisms that I think are definitely Kirkian things that I wanted to use in my portrayal, but for the most part, I wanted to free myself up to create something new."

The director of the final four "Harry Potter" movies, David Yates, is still giving thanks for the young cast he inherited, led by Daniel Radcliffe as boy wizard Harry and Emma Watson and Rupert Grint as his school pals.

"There was something very, very, very clever in their choices. Not a day goes by I'm not grateful for this bunch they put together," Yates said. "It's a remarkable bunch of kids."

In "Harry Potter and the Half-Blood Prince," Harry is charged with uncovering a forgotten memory from a new Hogwarts teacher (Jim Broadbent), information the young sorcerer needs for his final showdown against dark wizard Voldemort.

While Yates marvels over how his youthful cast has blossomed, "Transformers" director Michael Bay was thrilled over the improved acting chops of his computer-animated robots for the sequel.

"We were just touching the surface last time in what they're capable of doing," Bay said. "This time, they really emote."

"Transformers: Revenge of the Fallen" reunites puny but plucky human Shia LaBeouf with his giant, shape-shifting Autobot buddies in a rematch against the evil Decepticon robot clan.

Also in a rematch are Tom Hanks and Ron Howard with "Angels & Demons," their follow-up to "The Da Vinci Code." This installment hurls Hanks' symbologist into an ancient feud between the Vatican and a secret brotherhood that has kidnapped the cardinals in line to become the next pope.

Howard felt less pressure this time adapting Dan Brown's best-seller than he had with "The Da Vinci Code," a literary phenomenon whose did-Christ-have-kids premise put the movie under a severe microscope by fans and detractors alike.

"Documentaries are being made about 'Da Vinci Code.' Theologians develop symposiums around it. Ministers were using it as a way to, frankly, entice people to church," Howard said, adding that the new film "remains provocative, yes, but it doesn't hold that same place at the center of the zeitgeist. So it's really full-on escapism.

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