One of the odd things about the Alien series is how each film has managed to strike its own tone entirely separate from its predecessors. Ridley Scott’s original Alien was a good old-fashioned scare-the-pants-off-you haunted-space-ship movie. James Cameron’s Aliens was more of an action-adventure flick. And David Fincher’s unjustly maligned Alien3 was the most brooding, thoughtful, and bleak film in the series.

If anything, the latest installment in the Alien series, Alien Resurrection, is probably most closely linked with Alien3, in that it builds on plot lines developed in the third film and likewise takes a more leisurely approach to the thrills and chills. But in an important distinction between the two, the newest chapter in the Alien saga brings a touch (warped as it may be) of humanity and optimism to the saga of Ripley (Sigourney Weaver), while also striking a surprisingly light-hearted, even humorous tone. (This may come as no surprise when you consider the screenplay is from Joss Whedon, whose previous films include the animated family comedy Toy Story and the tongue-in-cheek Buffy the Vampire Slayer.)

Two hundred years after Ripley throws herself into a pit of molten metal to kill the alien living inside her, scientists aboard a military medical research ship have gotten hold of Ripley’s DNA and have successfully cloned her and removed the alien “fetus” living inside her. Their plan is to breed and domesticate the aliens for military and scientific use, proof once again that hundreds of years and all the technology in the world haven’t made people one lick smarter.

Into this scenario comes the pirate ship Bette, carrying kidnapped humans who will be used as human incubators for the new aliens. Also on board the Bette is the mysterious Call (Winona Ryder), who takes an unusual interest in Ripley.

Despite the military’s best-laid plans, the aliens soon escape, the carnage begins, and our heroes begin a frantic, Poseidon Adventure-like race to get to the Bette and escape.

With good turns by Ryder and Ron Perlman as the brutish Johner, Weaver’s Ripley is once again firmly at the center of the action of Resurrection. And at age 50, she gives us an action hero who could more than stand up to the likes of Sly, Arnold, Ford, or Costner.

One unexpected side effect of the genetic tinkering is that some characteristics of the alien DNA have mixed with Ripley’s, resulting in her having increased strength, coordination, heightened senses, and, like her otherworld nemeses, acidic blood. In short, Ripley, never a shrinking violet, is now a bad ass. (One of the coolest scenes ends with Weaver making an incredible one-handed, over-the-shoulder three-point basketball shot, and yes, she really did make it.)

But she’s a bad ass with a little bit of an identity problem.

One of the keys to the Alien series’ success – besides the creatures themselves – has been Weaver and the unique perspective of having a female protagonist in an action film, a genre usually dominated by men. The character of Ripley and the nature of the aliens themselves – they plant their young inside “host” organisms until they reach a certain level of maturity, at which time they burst through the host body, killing it – has allowed the Alien series to explore ideas about motherhood and rape while still managing to entertain. It’s what the very best science fiction does: distance sensitive subject matter so that it can be looked at with fresh eyes.

In Resurrection, Ripley continues to struggle with the implications of her rape by the creature in Alien3, but now has the added dilemma of discovering herself after having died and been brought back as the most successful in a series of cloning attempts. The new Ripley is disturbingly detached as she tries to make sense of all this. It is a shaded and subtle performance for Weaver, but a change in the character that distances her from the audience.

With top-notch special effects, production design, and performances, much of Resurrection compares favorably with the previous films. One mistake that director Jean-Pierre Jeunet (whose previous films include the well-worth-checking-out Delicatessen and City of Lost Children) makes is that he shows us entirely too much of the aliens, a bad habit of all the post-Scott directors. Maybe after four films it is asking too much for audiences to be frightened every time they see one of these slobbering, fanged monsters, but Jeunet goes too far in the other direction. We become too familiar with the aliens, to the point that they take on personalities, something which does provide some nice comic moments but which also robs the story of some of its dramatic weight.

This habit of identifying with the aliens does work to good advantage, however, in the movie’s final act, when a new alien makes its appearance – one that is, in a way, more frightening than all the others because it is the most human. (The new alien, by the way, makes its appearance by way of the most out-of-left-field plot twist I’ve seen in quite awhile, one which, I’m sorry to say, I’m still struggling to understand.)