We’ve witnessed, this summer, how fresh blood can rejuvenate a franchise entering its third installment. Weeks ago, Paramount handed the Mission: Impossible keys to J.J. Abrams (Alias) and clicked their heels when the inventive television director breathed new life into a financially healthy but creatively stagnant series.

Fox attempts a similar trick with its valuable X-Men venture, though in honesty the studio had little choice. After conceiving two blockbuster films that delighted both critics and fans, director Bryan Singer walked away from the X universe for the chance to direct the next Man of Steel movie (his Superman Returns arrives in theaters next month). Fox wouldn’t let Singer’s exit kill its golden-egg-laying goose, so the studio plopped oft-maligned hired gun filmmaker Brett Ratner (Rush Hour) behind the camera and prayed that he wouldn’t botch The Last Stand, reportedly the final installment.

Ratner’s a competent filmmaker more adept at meeting deadlines and delivering on budget than he is at stimulating imaginations, so it’s no surprise that his take on the X-Men tows the company line. Singer’s X-Men movies professed sincere love for the Marvel Comic characters - mutant superheroes shunned by the society they swore to protect. Instead of catching up on vintage X-Men stories for inspiration, Ratner appears to have downloaded Singer’s visions and religiously followed his lead. The Last Stand works as a sufficient conclusion to the series Singer started, but any connection these films had to the original comics has faded away.

Credible story lines can be hard to come by during Hollywood’s summer season, yet The Last Stand finds three worth exploring. The film’s main plot involves a mutant "cure" devised by scientists at Worthington Labs, headquartered on Alcatraz. With an official blessing from the President of the United States, Dr. Kavita Rao (Shohreh Aghdashloo) promises vaccinations for mutants wishing to shed their powers and lead “normal” lives.

The idea of a cure upsets Magneto (Ian McKellen), a concentration-camp survivor himself who wants no part of humans stripping his might. He rebels by recruiting an army of evil mutants - comic fans might call it a brotherhood - to march on San Francisco.

Meanwhile, back at Xavier’s School for Gifted Students, the X-Men confront their feelings in the wake of Jean Grey’s death - she sacrificed herself to save the team at the conclusion of X2. Cyclops (James Marsden) leaves Wolverine (Hugh Jackman) and Storm (Halle Berry) in charge of the new recruits. He bolts before hearing clues that suggest Jean might not be dead after all.

All three stories trace back to popular plot arcs from the X-Men comics. Jean is reborn as the Dark Phoenix, which some consider to be the strongest comic story ever written. That one thread alone could have supported three X-Men films. Here, it shares time with the cure plot pulled from Joss Whedon’s recent X-Men books and an indifferent Magneto plot to impart his will over humanity.

It’s too much material for one movie. Last Stand has as many characters as a deck has cards. The thrill of seeing Vinnie Jones in the Juggernaut suit or Kelsey Grammer as the blue-haired Beast is squashed once you ultimately realize they contribute nothing to the story. Co-screenwriters Simon Kinberg and Zak Penn can’t address each character in detail - the movie would run an additional three hours. As a result, some are killed off quickly, others are forgotten for long stretches, and all, save for Wolverine and Storm, have their potential wasted.

However, The Last Stand isn’t a disaster. It’s better than the rabid fans expected from Ratner, but marginally worse than eager studio heads probably desired. What works? There’s a eye-popping Danger Room sequence tossed in to appease die-hards that hints at robotic Sentinels. And the third time’s the charm for Jackman, who finally owns the Wolverine role. Ratner’s decent effects actually serve the story, including a Golden Gate Bridge stunt that’s worth the price of admission. Plus, the geek in me has to admit that there’s a certain nostalgia to finally seeing the five original X-Men - Beast, Angel, Iceman, Cyclops, and Jean Grey - in the same flick, even if they never share the same scene.

Ooooh, dad is gonna be pissed!