Teacher Sam Decker has had enough and is getting ready to quit his job. He wanted to make a difference in children's lives after serving in the Gulf War but at this school there is no place for people who care. The school he works in is one of the toughest and so nothing matters here and the only option left is to call it quits. The day that he hands in his notice he does one more round of detention duty and some of the toughest students are in this detention. It ends up being a very bad for everyone involved.
The school becomes a full out war when some criminals decide to run into the supposedly abandoned high school and use it to get away with $300 worth of cocaine. These are no ordinary criminals however, they are a well organized group of murderers. They plan to hide the cocaine in two police cars by using the school's auto-shop and take off with the cocaine.
When they enter the building they are shocked to find Mr. Decker and his detention students still in the building. The game of cat and mouse is on as both students and teacher are forced to run and hide to protect themselves while the criminals use the security camera's to hunt them down.
The students and Mr. Decker soon band together to fight off the criminals and survive their time inside the school. As they fight the criminal's off and try to find a way to get free, they find out that this whole thing is a conspiracy that goes up through the police department and even higher up in the government. Even the school security guards are in on it and were supposed to make sure that the school was completely empty.
The lesson being learned during this detention is survival and the kids start learning some tricks and tips from Mr. Decker. Not only are the students learning something from Mr. Decker, Mr. Decker is learning some stuff from his students.