Combine the action of “Star Wars” and NBC’s “Heroes,” mix in the touchy, awkward “true love” drama of “Twilight” and sprinkle in an unhealthy helping of alien activity worthy of a Trekkie convention and you’ve got “I Am Number Four.”

Film fails at box office

The new sci-fi thriller meets chick flick adaptation of a young adult novel by the same name was released Friday and earned second in the weekend box office, despite predictions that it would be an easy first. “I Am Number Four” was expected to draw droves of high school teens, both action-starved guys and heartthrob-hungry girls, but fell a little short, raking in less than $20 million.

Plot confuses

Most likely, this disappointment should be chalked up to plain confusion. Even after seeing the trailer a good three or four times, you still don’t really know what you signed up for until you get to the theaters. Is it “Terminator” for the Twitter generation? Is it the sequel to “Breaking Dawn,” this time with aliens instead of vampires? What do I care if he’s Number Four, and where did the first three go?

Well, the first two questions are still up for debate, but the last one does get a sensible answer 20 minutes into the film. Number Four is one of nine teenage aliens from a planet called Lorien — Lord of the Rings reference noted — living as refugees on Earth after their entire planet was ravished by the evil Mogadorians. These nine, destined from birth to be protectors of their race, gain unique, superhuman powers as they grow older, and are the only obstacle standing between the Mogadorians and their new target: Earth.

Film struggles to graduate from high-school themes

In the opening scene, you witness the hunt and murder of Number Three in some dark jungle and the immediate mental and physical effect this death has on Number Four, who you find spring-breaking on the beach. Played by 20-year-old British actor Alex Pettyfer, the blond, tan, surfer version of Robert Pattinson, Number Four, or John Smith as he goes for the remainder of the film, receives a vision and a burning scar that warn him he’s next to die — yes, even a Harry Potter reference made it in somehow. John and his guardian, Henri (Timothy Olyphant) hightail it to Paradise, Ohio, where John insists that he be allowed to attend school. Henri reluctantly lets him go, cautioning him to keep a low profile.

Soon, the shy, strapping young lad meets the shy, breathtaking young lady, Sarah Hart. Many might recognize actress Dianna Agron from her teen mother ex-cheerleader role in Glee, and, against all odds, she plays an ex-cheerleader outcast in “Number Four” as well. In love with photography, Sarah soon finds a mysterious subject in John, and love at first sight would be something of an understatement for the pair of them. John also makes a friend in nerdy, UFO-obsessed Sam (Callan McAuliffe), and an enemy in homecoming king/quarterback/Sarah’s ex-boyfriend Mark (Jake Abel). All in all, it’s the quintessential, cheesy-to-the-max high school setup, with extraterrestrial complications.

From there, the movie becomes a tale of two desperate struggles. One involves a looming fear of the constant, narrowing pursuit of the Mogadorians, a band of freakishly tall, tattooed Goth aliens with some kind of fire blasters and a couple of gigantic, demonic flying squirrels with fangs. The other struggle focuses on the tension between John and Mark, mostly over Sarah. Slowly, John’s powers begin to manifest themselves in episodes called “Legacies,” and he becomes a force to be reckoned with. Whether that force will be enough will come into question by the grand finale — which takes place on a high school football field.

Unoriginal and semi-impressive

Had “I Am Number Four” used a shred of original material, it’s semi-impressive graphics, highly entertaining action sequences and new-kid-in-school (not to mention galaxy) feel might have made for a nice alternative to the vampires versus werewolves craze. Instead, a sub-par cast, a purposeless plot and an inability to surprise the audience with anything new left “I Am Number Four” somewhere in the atmosphere of Pluto — inadequate and soon to be forgotten. Since the book is expected to be the first of a six part series, the film clearly left room for a sequel. Let’s just hope “Number Five” has something out of this world to offer.