After the nuclear holocaust that occurred in “Terminator 3: Rise of the Machines,” very few survivors are left on Earth. Led by John Connor (Christian Bale), they struggle to survive and keep their hope alive, yet again. Skynet, the A.I. that rebelled against humanity many years ago, is determined to exterminate every human with the use of terminators.

Unlike the last three “Terminator” movies, this movie introduces a robot-human hybrid named Marcus Wright (Sam Worthington). A couple decades ago, the murderer donated his life to a government experiment that would supposedly help humanity. He felt guilty of what he had done and believed he wasn’t worth anything.

Years later, Marcus wakes up and finds the world void of life, save for Kyle Reese (Anton Yelchin), John’s father in the first “Terminator” movie, and Star (Jadagrace), a child who happens to have every weapon available to this ragtag team. After a half hour of wondering where this movie is going, they hear a radio broadcast from John Connor. He requests help from anyone alive and ready to fight the machines for round four.

Marcus may seem like the one who can save humanity, but John has a problem with him: he’s  made of the same material that killed the Connor family. Nevertheless, Marcus wants to prove that he’s not just a robot, which is odd considering that he felt like a nothing when he signed up for the robotic transformation. He sides with John and becomes his endearing lapdog by going into the center of Skynet.

Though it’s fun to watch humans come up with new ways to destroy the very things they created, the battles are often frustrating because the robots just won’t die.

Launch two grenades into their systems, they’ll reattach themselves. Light them up with gasoline and matches, they’ll cool themselves. Nuke them — well, maybe that will do something to them. But the movie isn’t entirely tedious. The special effects are definitely top of the line, and they help when scenes get boring.

Indeed, “Terminator Salvation” does not fail to show that humans will split up and also unite in times of crisis, there is still no need to prove this bout the fourth time around while it juggles the savior title among three different characters.

Twenty years ago, the “Terminator” movie was fun and an interesting concept with the computers versus humans. The low budget movie was received well by viewers and made a whopping $78 million. The producers should have let the legend live and ended the series with the second movie in 1991.

The same magic does not work again in 2009. Nobody really cares who the savior is anymore, especially when the future gets reset after each new movie.

“Terminator” may say “I’ll be back” in every movie — oh, no. Please don’t come back.