It's X-Men meets The Breakfast Club. When five superhero teens are hauled into detention at their secret training academy, they have to work together to stop the sinister Kaelus from stealing all the students' powers.
At a high school for super-heroes in training the school is preparing for the arrival of the world's main super-hero, Kaeluss, who is coming to select his replacement in the hero business. As the school prepares, Principal Hughes rounds up a handful of students who are then locked in detention for the duration of the visit. In a large assembly room the faculty and students are anxious for the hero's arrival. Kaeluss arrives with his super-powerful entourage and tells the principal that the device he brought with him will test the students' powers and reveal who his successor will be. Before the tests can get underway, Hughes hears the kids in detention fighting and he goes to watch over them, missing the assembly.
After each student is tested, Kaeluss reveals that he is actually there to steal all of their powers and take them as hostage as he turns the school into his new fortress and ensures his place as the world's only super-hero. Once victory is secured, Kaeluss' assistant discovers that not all students were at the assembly but were in the building in detention. She goes to retrieve them and a fight breaks out and the kids learn what is really going on and vow to save their friends while Hughes calls for help.
The would-be heroes confront Kaeluss, but loose and make their escape, only to spend quite a bit of time hiding from and fighting Kaeluss' henchmen and women. All the while, Klon, one of the students from detention is reluctant to help them and keeps to himself. While the students are fighting, Hughes gets to his office and calls his supervisor, Mr. Kent, to send help; only to learn that Kent is in league with Kaeluss, who then arrives and captures Hughes.
With Hughes now captured, the rest of the heroes (less Klon who left) goes to strike a deal with Kaeluss and they agree to give up their powers if he'll set the students free. He lies and says he will, but once the heroes are powerless, he goes back on his word. That's when Klon returns and it is revealed that Klon is really a clone of Kaeluss that Hughes freed from the lab and brought to the school. When all seems lost and the students are defeated, one of the girls from detention, who was really a werewolf, changes and attacks Kaeluss, defeating him as Hughes is able to reverse the machine and restore everyone's powers.
It ends with all of the kids from detention being really good friends now; Klon being less of a loner and Kaeluss about to be shipped off to prison. However, his top assistant comes in to see him before he leaves and her eyes glow (as she has heat/laser vision) and the scene cuts away.
