Hank (Steve Zahn) and his partner Charlie mistakenly decide to answer a cancelled call to check on an alarm at a warehouse. When they arrive on the scene they split up and Charlie comes under fire, Hank tries to save him but Charlie ends up being shot by one of the assailants. On the other hand there is Earl (Martin Lawrence) who is attempting to pass through Police Academy, but is just too much of a showoff for his own good. The two meet on the street as Earl tries to get in to his locked car, Hank accosts him thinking that he is a thief. Through some bumbling and misunderstanding Hank is relieved of his duty as a cop and spends some time in jail, all thanks to Earl. Before long though, the two of them end up on the case trying to determine who killed Charlie together, but as security guards, which is something that Hank has always detested. They discover that the killer's name is Nash (Eric Roberts) and they go after him with a vengeance. Will they end up with more than they can handle, or will the two 'National Security' security guards end up solving the case and saving the day?