Sigourney Weaver is back once again as Ellen Ripley, a role she once received an Academy Award nomination for. And she is again fighting off those evil aliens in this fourth chapter of the series, “Alien Resurrection.”

Hold on a minute. Didn’t Ripley die at the end of the last movie? I distinctly remember her throwing herself into some sort of flaming pit. Well, now government scientists have cloned her. What they want to do is extract the alien queen Ripley was carrying.

The scientists cloned Ripley from a blood sample they got out of a mosquito trapped in petrified amber. Oh, wait a second. That was “Jurassic Park.” It’s never made clear where they were able to find a blood sample after 200 years. A lot of things in this movie are never made clear.

Their plan is to breed the aliens and use them as slaves, to train them to be used in battle. The centuries that have passed between the end of “Alien 3” and the beginning of “Alien Resurrection” may explain why these guys are stupid enough to revive the aliens and think they can be controlled.

Didn’t they see the first three movies in the series?

Of course the aliens get lost. Of course the aliens start breeding like crazy. Of course the aliens start indiscriminately ripping humans apart. “Alien Resurrection” is a dark, wild ride from this point on, definitely the most twisted of the series.

A lot of the movie becomes things we’ve seen before. The aliens jump out and grab people. We see their long fingers coming up through grates in the floor. Those creepy face-hugger larvae scurry around like giant spiders and attach themselves to people’s faces.

What’s different this time around is Ripley. She may or may not be part alien due to the cloning procedure. Can she be trusted? On top of that concern, in “Alien Resurrection,” Ripley is just a bit nuts. More accurately, she’s completely whacked out. We’re never sure which side she’ll end up on.

The cloning theme sets up the most interesting scene in the entire movie. In a wonderfully disturbing segment, Ripley is faced with seeing the failed attempts at clones. They’re all kept in large glass tubes and are bizarre and grotesque hybrids of human and alien.

Another great scene is a spectacular underwater chase near the end of the film. It was thrilling to see the hideous aliens glide gracefully through the water after their human prey. After a few minutes though, I began to wonder just how long these humans could hold their breath.

Speaking of “these humans,” the cast of the movie is a little on the flat side. I never really cared if any of them got killed by the aliens. This makes the chase segments a little less thrilling. And Winona Ryder, as Call, seems a bit out of place in a film of this type.

The characters dialogue is another problem. These people seem to speak only in sassy one-liners and smart-ass comebacks. It’s like the movie is straining to contain this year’s big catch phrase, the “Show me the money!” of 1997.

What I want more of is the aliens. They need more character development. Yes, I know that sounds crazy, but they really are interesting creatures. There are a few bits where they show their intelligence by figuring out how to escape and such, but not enough to satisfy my curiosity.

“Alien Resurrection” ends up being merely OK. There are some thrilling moments and moments when you’ll want to cover your eyes. Bits and pieces of it are great, but overall there’s not much new here.

3 stars out of five.

Mike Milik is a senior in advertising from West Des Moines.